Not how it works; that's leading the witness, and just because you are an expert in one field (comparing code) doesn't mean you are an expert in another (assess

Not how it works; that's leading the witness, and just because you are an expert in one field (comparing code) doesn't mean you are an expert in another (assessing the value). I've actually been in this exact situation as an expert witness. The defendant had written code in language "A", sold it, then wrote similar code in language "B". The question was whether code "B" had been written while looking at code "A". The answer was yes, and I could prove it. Code often has a history that's apparent (e.g., you throw in an if statement to catch a weird input, and you add a comment like "fixing the wheelabrator-fry issue from december"). New code won't have the same history, and therefore should not have the same structure. If it does, the code must have been copied. That's especially true if there are dated comments in the code. What I wasn't asked was the economic value of the copying. Other experts handled that; I was just an expert in the two languages. BTW: the final assessed value was much less than the cost of the trial. And I felt sorry for the defendant; most of the code had not been copied.