Interesting observation, but to me, any episode produced after 1978 is a goof, if not just plain Murder With Too Many Notes!

Columbo did not make up or create any evidence which was going to be presented in court during the trial. I believe that was the nature of the question asked of him by the student.

Yes, I guess that is true. It's not the made-up evidence that condemns the killer; it's the killer's reaction to it.