Now that I think about... Gallus' challenge in "What Lies Beneath" makes no sense. What does claustrophobia have to do with friendship? Plus, Gallus could've been killed if he failed.
I assume the challenges wouldn't have caused any actual physical harm to the students... That would have been really cruel. I guess he'd just have been stuck there.
Spoiler
Though that still means he could have starved to death.