I don’t know if that kind of temperature lasts more than microseconds, so that might not be enough time for much combustion to happen.
In any case, the forces from a 300 atm pressure differential would mash the people to goo in the blink of an eye. Like being inside an exploding bomb. Except exploding in. They’re fish food.
EDIT: There are reports that the Coast Guard recovered “presumed human remains”.
https://www.theguardian.com/world/2023/jun/28/titan-sub-debris-implosion-wreckage-oceangate
What could possibly be left of them after that implosion?
How’s firing almost all your IT staff working out for you, Elon?