The MC isn't an idiot. The majority of people commenting that he is one are the idiots. Yes he's strong but he has ZERO reason to assume that. He's still going off game knowledge, a lot of which is not widely known apparently. The skill the examiner used is one that his game knowledge tells him...
This what happens when you try to railroad your players, even if it is for their own benefit. They go off and be stupid. Too bad he can't just let a TPK happen.