Seemingly unkillable monster that has, for the entire film, proven itself to be unkillable gets "killed" only to murder the person who is standing ontop of the dead/not dead monster while looking back at the rest of the group.
Like, seriously, you know the thing isn't easy to kill. Why suddenly lose all sense of self preservation and paranoia about the monster's leathal state?
Honorable mention to the "unecessary sacrifice" where a character "bravely" stands in the way of the monster (who tears through them like tissue paper) instead of running away to give the rest of the characters something like .001 second more time to run away.
Yes.