Rear engine in a crash question

I've been reading through the BD-5 thread and have a question.

I guess this is an opinion thread but what happens to a rear engine
mounted directly behind the pilot in a crash? In something like an
ultralight, BD-5, Cutiss pusher or Vari-EZ does an engine have a
tendency to rip loose and go through the pilot due to inertia in a
sudden stop? Or in many crashes is the direction of flight not straight
ahead, like if the aircraft was in a stall when it contacted the ground?
The force is down not forward through the cockpit.

Bernadette