I suppose, although if the student is able to show the prof with the tools that the chip they have (which based on the story should be visually identical or very similar to the rest of the chips) behaves incorrectly, that test can be repeated many times. It's possible the student could have acquired it elsewhere and is snowing, but even if that's the case the fact that they can do the analysis and show (and waited so long in the class to get there), and have the history of asking for help throughout the course, all add up to pretty powerful evidence IMHO. The prof could even do his own test with the chip if he doubts. It seems hard to believe that one student would intentionally try to "cheat" by making his life much, much harder. It's surely a path of much less resistance to just follow the book.