Thinking it over, what stops Freeza from just pulling a Revival of F and blowing up the entire battlefield at the bell?
The movie and anime proved he'll do ANYTHING to win, while Goku and Vegeta operate on standards.. Freeza's so manipulative, I wouldn't put it past him playing up an injury, acting defeated, then firing a Freeza Beam through his own body to kill Hit. I mean, why not? Hit can't time skip something he doesn't see until it makes a hole in his chest.