They're in the middle of a survival exercise that might be a full on actual survival scenario. It's not the time to go down a hero. Katsuki does not want to have an argument over whether or not Hawks shreds his wings to tiny pieces or sets them on fire or does the normal sane thing and get them washed off. He's not Hawks's mom. It's not his job to make the guy not be an idiot.

"It's not a big deal. Izuku'd help in a heartbeat." Katsuki could call him, and Izuku'd swing on over before Hawks made his next excuse.