Hmm...
My Robin ATL has an upwards opening lexan bubble canopy.
Perhaps the adrenaline rush would give the strength to fight my way out if upsidedown in a field. But trial attacks on a test piece of Lexan are not encouraging. Lexan is indeed tough stuff! Also swinging a crash axe in a small cockpit could decapitate my pax!
Seems like the AAIB are on to a problem that needs sorting.
MG