New practice on disputes on illegal use of source code in software development

The defendant developed a program for the plaintiff and several years later released its own product with identical functionality. Forensic examination in the first instance failed to establish similarity and redesign, the court dismissed the plaintiff. For cases where forensic examination is the key evidence, the possibility of overturning such a decision on appeal is usually assessed as very low. PATENTUS lawyers, led by Maxim Volkov, Deputy Head of the Dispute Resolution Practice, compared the codes independently and found that the defendant had "masked" the source code (the defendant originally had our source code) - that's what Maxim called non-functional changes to the code, which do not affect the code's performance, but exclude a match in traditional automated methods of source code comparison. The appellate court heard the arguments of our lawyers, summoned the expert for interrogation, and during the interrogation the expert could not convincingly explain why he had not noticed two identical code sections with comments (the sections were demonstrated in the session as an example) when he was conducting the expert examination. As a result, the decision was canceled and the claim was satisfied. At the same time, the court not only prohibited the use of the derivative work, but also recognized the plaintiff's rights to the defendant's program.