I was slightly paranoid about this when RAF QFI'ing in the Bulldog. (They were later fitted with a combined crash hammer / seat belt cutter, but I'm not sure how effective this would be).
I was known for getting very stroppy with students who set up a PFL towards a brown field - used to make them go around immediately.
PFL - ploughed field - engine fails to respond - real forced landing - nose over - unable to escape - leaking AVGAS - hot engine - no thanks!