I mean, they had to be right didn't they?

I used to sit in disbelief at the point-fighters in my Master's program at BYU. If I were a corporate recruiter, I'd skip interviews and just sit in a single class where they review a test. And start scratching people off my list.

I can specifically recall being embarrassed by these students.

It's possible this professor's question was flawed or incorrect, but from the OP's account, the students were waaaaaaay in the wrong.