Gideon Korrell Discusses Why Recusal Alone Didn’t Overturn the IPR Ruling

On October 22, 2025, the Federal Circuit issued a mixed but important decision in Centripetal Networks, LLC v. Palo Alto Networks, Inc. While the court rejected sweeping arguments about recusal and due process, it still vacated the Patent Trial and Appeal Board’s (PTAB) final ruling. The key reason was not bias, but the Board’s failure to properly evaluate evidence of copying an essential part of the obviousness analysis.

As Gideon Korrell explains, this case shows that procedural challenges alone rarely decide appeals. Instead, substantive legal errors often carry more weight.

Background of the Dispute

The case arose from inter partes review (IPR) proceedings involving claims of U.S. Patent №9,917,856, which relates to detecting threats in encrypted network communications.

• Palo Alto Networks filed the initial IPR petition
• Cisco Systems and Keysight Technologies later joined
• The PTAB ultimately found the claims unpatentable as obvious

However, complications emerged when it was discovered that one administrative patent judge (APJ) owned stock in Cisco.

The Recusal Issue: Timing Matters

Centripetal argued that the APJ’s financial interest required recusal and invalidated the entire proceeding. But the Federal Circuit disagreed.

Why the Argument Failed

• Late filing: Centripetal delayed raising the issue despite public disclosures
• Strategic timing concerns: The motion came after unfavorable rulings
• Administrative efficiency: PTAB timelines require prompt objections

Gideon Korrell notes that courts are often skeptical of recusal arguments raised late in the process. Even valid concerns can lose force if not raised in time.

Ethics Rules and Financial Interests

The court also examined whether the APJ violated federal ethics laws.

Key Findings

• Ownership under $15,000 is permitted under federal regulations
• The rule is not just a defense; it defines acceptable conduct
• No violation occurred because the APJ stayed within limits

The court rejected broader claims about “appearance of bias,” emphasizing that specific regulations govern such situations.

Due Process Claims Rejected

Centripetal argued that PTAB judges should follow the same strict recusal standards as Article III judges. The court declined.

Court’s Reasoning

• PTAB judges are executive-branch officials
• Different legal and ethical frameworks apply
• No constitutional requirement mandates stricter standards

Gideon Korrell highlights that administrative proceedings operate under distinct rules, even when they resemble court trials.

Why Recusal Didn’t Lead to Vacatur

Even if there had been an issue, the court explained that recusal does not automatically invalidate prior decisions.

The Court Applied a Three-Factor Test

• Risk of unfairness to parties: Minimal
• Impact on other cases: Limited
• Public confidence: Not significantly affected

Additionally, the judge in question stepped down before the final decision, which was issued by a new panel.

The Real Problem: Ignoring Evidence of Copying

Although the procedural arguments failed, the Federal Circuit still vacated the decision for a different reason.

What the PTAB Did Wrong

The Board failed to properly consider evidence that Cisco may have copied Centripetal’s technology. This included:

• Meetings between the companies
• Internal communications referencing the patent
• Expert testimony suggesting copying

Instead of analyzing this evidence, the Board dismissed it because it came from related district court proceedings.

Why Secondary Considerations Matter

In patent law, secondary considerations like copying help determine whether an invention is truly nonobvious.

The Court’s Position

• These factors are mandatory, not optional
• The PTAB must evaluate them when presented
• Ignoring them is a legal error

Gideon Korrell emphasizes that even strong technical arguments for obviousness can fail if objective evidence is overlooked.

Key Takeaways for Practitioners

This decision offers several practical lessons:

• Raise recusal issues early to preserve credibility
• Understand that the ethics thresholds are clearly defined and enforced
• Do not rely solely on procedural challenges
• Develop strong secondary evidence, especially copying and industry behavior

Most importantly, the case reinforces that appeals are often won on substantive analysis rather than procedural claims.

Conclusion

The Federal Circuit’s decision makes one point clear: recusal alone is rarely enough to overturn an IPR ruling. While fairness concerns are important, they must be timely and grounded in applicable rules.

In this case, the decisive issue was the PTAB’s failure to consider key evidence of copying. As Gideon Korrell explains, this serves as a reminder that secondary considerations remain central to patent validity analysis and cannot be ignored.