Cormac doesn't know what to think. The task was being really exciting, although he didn't really get what was going on with Krum, and then... that.
He's in shock over Cedric's death. He didn't really know him that well, but he never wished him no harm, only defeat. He also feels terrible for Allegra's sake and will try to help her deal with this, though he'll understand if she'd rather spend this time with her uncle and aunt.