The teacher's point explanation is fucked here,
Gu Yue is the real problem as she baited a monster to her allies which should negate any points in saving Wulin from shattering, on top of not knowing about the beast.
Xie Xie didn't know about the freezing either, just that the neck was a weak point, other than that his usefulness was exactly as Wulin had said.
Wulin was the linchpin in actually being able to deal a finishing blow and served just as much as the others did, if not more since he had previously saved Xie Xie as well as finished the beast that had attacked him.
And for the others that scored 0 and 1, the 0 made no sense as he made the right choice in hitting the distress beacon,
if that 0 was truly deserved, the 1 should have been a 0 for not hitting the distress beacon before dying.