In patent infringement suits, the reliance on expert testimony plays a pivotal role in establishing the validity of claims and determining the likelihood of success. However, the issue of whether expert affidavits can be considered without cross-examination has sparked debate within legal circles. This article examines a recent case where the court declined to grant interim relief in a patent infringement suit, inter alia emphasizing the necessity of cross-examination in assessing expert evidence.

Background of the Case:
The subject matter of the suit revolves around the infringement of a patent titled "Novel Agricultural Composition." The original claim in the patent did not mention the conversion of sulphur to sulphate, but later amendments modified the concentration of sulphur as the active ingredient. The defendant argued that the features of the claimed composition were already disclosed in a prior application (App 655), leading the court to decline interim relief in favor of the plaintiff.

Court's Observations:
While declining relief, the court scrutinized the practice of relying on expert affidavits without subjecting the experts to cross-examination. The court expressed doubts regarding the advisability and permissibility of placing reliance on such evidence in patent suits. It emphasized that neither side admitted the veracity of the opposing party's affidavits, and the experts had not been cross-examined. Consequently, the court questioned whether the merits of the case could be decided solely based on untested expert evidence.

The court highlighted the importance of cross-examination in testing the credibility and reliability of expert testimony. Without the opportunity for cross-examination, the court argued, expert affidavits cannot constitute the basis for granting or rejecting interim relief in patent infringement cases.

Legal Analysis:
The reliance on expert evidence is common in patent litigation, where technical complexities often necessitate expert opinion to interpret claims and assess infringement. However, the efficacy of such evidence depends on its thorough examination and testing through cross-examination.

Cross-examination serves as a crucial mechanism for uncovering inconsistencies, biases, or limitations in expert testimony. It allows opposing parties to challenge the expertise, methodology, and conclusions presented by experts, thereby ensuring a fair and robust adjudication process.

In the absence of cross-examination, the reliability and credibility of expert affidavits may be called into question. Unchallenged expert evidence runs the risk of being one-sided and may not provide a comprehensive understanding of the technical nuances at play in patent disputes.

Conclusion:
The case underscores the significance of cross-examination in patent infringement cases and the limitations of relying solely on expert affidavits. Courts must exercise caution when assessing expert evidence and ensure that it undergoes rigorous testing through cross-examination to establish its credibility and reliability.

Case Title: Sulphur Mills Limited Vs Dharmaj Cropguard Limited and another
Order Date: 18.03.2024
Case No. CS(COMM) 1225/2018
Neutral Citation:2024: DHC: 2154
Name of Court: High Court of Delhi
Name of Hon'ble Judge: C Hari Shankar, H.J.

Disclaimer:
This article is meant for informational purposes only and should not be construed as substitute for legal advice as Ideas, thoughts, views, information, discussions and interpretation perceived and expressed herein are are subject to my subjectivity and may contain human errors in perception, interpretation and presentation of the fact and issue of law involved herein.

Written By: Advocate Ajay Amitabh Suman, IP Adjutor - Patent and Trademark Attorney
Email: [email protected], Ph no: 9990389539