I can only think of a few reasons to jump out of an aircraft if it wasn`t being `stunted and bunted` at the time;
loss of the prop which may take it out of the C of G envelope;may have broken engine mounts..
`Flutter` of the elevator/tailplane,although it looks like half the tailplane and both elevators are intact;
Massive fuel leak into the cockpit,assuming fuel tank is fwd of front seat..
And I`ve had experience of both the last two whilst testing for the PFA(as was)...