I mean anyone who ever did any instruction knows that if your goal is to fail someone, you almost certainly can find a valid reason no matter how prepared they are. It's just a matter of digging until you find a weak area then hammering until they trip up. It's a truly scummy thing to do, especially since in this industry you either have a perfect record or are damaged goods.

I've known a few instructors who started treating evaluations like their opportunity to make the applicant feel like an idiot, but I've been lucky enough to avoid that kind of personality at the airlines.