Kutti Bay Investments Pty Ltd v Rattlejack Innovations Pty Ltd [2026] FCA 422
| Date of decision: | 13 April 2026 |
| Body: | Federal Court of Australia |
| Adjudicator: | Justice Rofe |
Introduction
Justice Rofe of the Federal Court of Australia has delivered yet another decision in the long running dispute between Kutti Bay Investments Pty Ltd (Kutti Bay, formerly Jusand Nominees Pty Ltd) over patents for a “Safety System and Method for Protecting Against a Hazard of Drill Rod Failure in a Drilled Rock Bore”. In this decision, Justice Rofe held that Kutti Bay’s application to amend three standard patents (the Standard Patents) constituted an abuse of process, insofar as it sought to “overcome” the Court’s decisions in Jusand Nominees Pty Ltd v Rattlejack Innovations Pty Ltd [2022] FCA 540 and Jusand Nominees Pty Ltd v Rattlejack Innovations Pty Ltd [2023] FCAFC 178 (the Jusand Proceedings). See our reports on these decisions here and here.
Background
Kutti Bay commenced proceedings alleging infringement of the Standard Patents against Rattlejack Innovations Pty Ltd, Pan Australis Pty Ltd, Murray Engineering Pty Ltd and Leigh Maurice Sutton (together, Rattlejack). Shortly after commencing proceedings, Kutti Bay applied to amend the Standard Patents under s 105(1) of the Patents Act 1990 to correct “obvious mistakes” in the Standard Patents. Rattlejack opposed Kutti Bay’s patent amendment application, ultimately on the basis that the amendment application (and the expert evidence intended to be relied on for the purpose of that application) gave rise to an abuse of process.
So, what was the basis for Rattlejack’s abuse of process allegation? The answer to this question requires us to delve into the previous patent disputes between these parties, which led to the decisions in the Jusand Proceedings.
In the Jusand Proceedings, Rattlejack had successfully defended Jusand’s allegations of infringement in respect of three innovation patents (the Innovation Patents). The Federal Court (at first instance and on appeal) had also found the Innovation Patents to be invalid for lack of disclosure and support. Relevantly:
- the Standard Patents had the same priority date as the Innovation Patents;
- the Standard Patents (in their unamended form) were in materially the same terms as the Innovation Patents. The Standard Patents were also in substantially the same terms as each other; and
- in the Jusand proceedings, the Court had made findings as to the construction of the Innovation Patents and as to the common general knowledge.
In November 2024, IP Australia re-examined all the patents in the same patent family as the Innovation Patents, including the Standard Patents. The examiner considered that each of the claims of the Standard Patents lacked disclosure/support, for the same reasons as those identified in the Jusand Proceedings. Given the examiner’s view, Kutti Bay considered it necessary to file the current patent amendment application to prevent revocation of the Standard Patents.
Kutti Bay relied on the evidence from three new expert witnesses, none of whom gave evidence in the Jusand Proceedings. Justice Rofe noted that it was clear in the case of one of these experts that he did not read the Standard Patents to describe and claim the same invention that the Court found to be disclosed and claimed in the Innovation Patents. Her Honour also noted that the conclusion of a second expert as to the routine nature of material selection was at odds with the findings in the Jusand Proceedings, and that this conclusion was only available based on an enlarged body of common general knowledge beyond what was found to exist on the evidence at first instance during the Jusand Proceedings.
Key Issues
When can a patent amendment be considered an abuse of process?
A patent amendment application may constitute an abuse of process where it seeks to re-agitate issues already finally determined by a court, undermine the effect of earlier judgments, create a risk of inconsistent findings, or unfairly prejudice another party.
Rattlejack filed an application alleging that Kutti Bay’s amendment application constituted an abuse of process to the extent that it sought to “overcome” the decisions in the Jusand Proceedings, for the following reasons:
- The amendment application sought to re-agitate and/or challenge issues of construction determined by the Full Court.
- The amendment application sought to invoke the Court’s statutory power in a manner that would undermine its earlier decisions.
In these circumstances, Rattlejack argue that allowing the amendment application to proceed would bring the administration of justice into disrepute, create a material risk of inconsistent findings and prejudice Rattlejack (including by exposing Rattlejack to being “twice vexed”).
Kutti Bay, however, argued that no such abuse of process arose as the proposed amendments merely corrected an “obvious mistake” in the Standard Patents, that is, a mistake which was apparent on the face of the Standard Patents and for which the correction was also obvious.
Consideration
Can a previous court decision concerning one patent affect related patents in the same patent family?
Yes. A previous court decision concerning one patent can affect related patents in the same patent family where they are materially identical and share the same priority date. In the Kutti Bay proceedings, Justice Rofe held that a later patent amendment based on new expert evidence would require the Court to reconsider its earlier construction of materially identical patents, amounting to an abuse of process.
Justice Rofe held that Kutti Bay’s patent amendment application was an abuse of process for the following key reasons:
- On the basis of the evidence before it, the Court in the Jusand Proceedings had made findings as to the common general knowledge of the person skilled in the art as at the priority date. The Court then construed the claims of the Innovation Patents, based on the findings as to the state of the common general knowledge at the priority date and assisted by the experts’ evidence as to their understanding of the claims.
- The Standard Patents were materially identical to the Innovation Patents construed by the Court in the Jusand Proceedings.The Standard Patents and the Innovation Patents also shared the same priority date.
- The amendment application, however, was premised on evidence which was not before the Court in the Jusand Proceedings and would require her Honour to reconsider the construction of the Standard Patents in light of this new evidence. More particularly, Justice Rofe held at [93] and [94] that:
“Kutti Bay’s “obvious mistake” contention requires the Court to read relevantly the same specification that it construed in the Jusand Proceeding, and in order to allow the amendment, agree with the new person skilled in the art experts that a different invention is actually described and claimed, than the one previously identified and considered by the Court.
As the Respondents identify, the vice in Kutti Bay’s approach is that in order to accept the existence of an obvious mistake, the Court must accept the evidence of the new experts as to the safety system of the claimed invention. Doing so would necessarily involve adopting a different construction of the claimed invention different from that reached in the Jusand Proceedings.”
Outcome and Implications
What happens if a patent amendment application is found to be an abuse of process?
If a patent amendment application is found to be an abuse of process, the Court may refuse the application to the extent it seeks to overcome an earlier judicial decision and may order the patentee to pay the other party’s costs. In this case, Justice Rofe ordered Kutti Bay to pay Rattlejack’s costs.
Justice Rofe held that Kutti Bay’s application to amend the Standard Patents constituted an abuse of process, insofar as it sought to “overcome” the Court’s decisions in the Jusand Proceedings. Justice Rofe also ordered Kutti Bay to pay Rattlejack’s costs of and incidental to its abuse of process application.
Justice Rofe’s decision is a salutary lesson for patentees: where construction of one patent in a patent family has already been the subject of a judicial decision, this construction may impact later litigation (including future amendment applications) in relation to other materially identical patents in the same family.
The proceedings continue, albeit very slowly, with the matter set down for a case management hearing in February 2027.
About Pearce IP
Pearce IP is a privately owned/independent, specialist, life-sciences focussed, intellectual property/law firm offering lawyers and attorneys in Australia and New Zealand.
Our lawyers and attorneys specialise in pharma, biopharma, biotech, ag-tech, food-tech, med-tech, although our work is broader than these industries.
Pearce IP and its leaders are ranked in every notable legal directory including: Chambers & Partners, Legal 500, IAM Patent 1000, IAM Strategy 300, MIP IP Stars, Doyles Guide, WTR 1000, Best Lawyers, WIPR Leaders, Best Law Firms, among others. In 2025, Pearce IP was honoured by Australasian Lawyer and New Zealand Lawyer as a Top Specialist Firm, 5 Star Employer of Choice, and the “Standout Winner” for Inclusion and Culture (<100 employees).
Pearce IP is the only leading IP firm in Australia and New Zealand with a female founder, and is certified by WEConnect International as women owned.
Helen Macpherson
Executive, Lawyer (Head of Litigation –Australia)
Helen is a highly regarded intellectual property specialist and industry leader with more than 25 years’ experience advising on patents, plant breeder’s rights, trade marks, copyright and confidential information. She is known for her expertise in complex, high-value patent matters and leverages her technical background in biochemistry and molecular biology to work across a wide range of technologies, including inorganic, organic, physical and process chemistry, biochemistry, biotechnology (including genetics, molecular biology and virology), and physics. Helen is an active member of the Intellectual Property Committee of the Law Council of Australia and the Intellectual Property Society of Australia and New Zealand.
Naomi Pearce
CEO, Executive Lawyer (AU, NZ), Patent & Trade Mark Attorney (Trans Tasman)
Naomi is the CEO and Founder of Pearce IP, and is one of ANZ’s leading IP practitioners. Naomi is a market leading, strategic, commercially astute, patent lawyer, patent attorney and trade mark attorney, with over 29 years’ experience, and a background in molecular biology/biochemistry.
Ranked in virtually every notable legal directory, highly regarded by peers and clients, Naomi is renowned for her successful and elegant IP/legal strategies focussing on complex/multijurisdictional litigation, global FTO, and strategic advice. Among other awards, Naomi is the 2026 Lexology Client Choice Winner for Patents, the 2024 Lawyers Weekly Women in Law “Executive of the Year”, the 2023 Lawyers Weekly “IP Partner of the Year”, the 2022 Lexology Client Choice Winner for Life Sciences, the 2022 Asia Pacific Women in Business Law “Patent Lawyer of the Year”, and the 2021 Lawyers Weekly Women in Law “Partner of the Year”. Ranked in Chambers Asia Pacific, Chambers Global, IAM Patent 1000, IAM Strategy 300, is a MIP “Patent Star”, and is recognised as a WIPR Leader for patents and trade marks.
Pearce IP is the premier life sciences focussed firm in ANZ. Commencing in 2017. Pearce IP is the 2025 Australasian Lawyer and NZ Lawyer 5-Star Employer of Choice & “Standout Winner” for Inclusion and Culture (<100 employees). In 2021, Pearce IP was the Lawyers Weekly Australian Law Awards IP Team of the Year.

Sally Paterson
Executive, Lawyer (NZ), Patent & Trade Mark Attorney (AU, NZ)
Sally is a senior Trans-Tasman Patent and Trade Mark Attorney, and a New Zealand registered lawyer with over 20 years’ experience in IP. Sally’s particular expertise is in life sciences, drawing from her background in biological sciences. Sally is well respected in the New Zealand IP community for her broad ranging skills in all aspects of intellectual property advice, protection and enforcement. Sally has extensive experience securing registration for patents, designs and trade marks in New Zealand, Australia and internationally, providing strategic infringement, validity and enforceability opinions, acting in contentious disputes including matters before the courts of New Zealand and before IPONZ and IP Australia, and advising on copyright and consumer law matters.
