[tcas]

I had the same experience when I was a TA a long time ago. Reviewing the code to a homework set I noticed that two students mixed up the naming of two variables (I think min/max were switched).

I ran a whitespace sensitive diff and noticed the only difference between the two files was the author name in the header.

The professor sent a sternly worded letter to the class about not cheating, and nothing else came from it AFAIK.