I used to fly skydivers in a cessna 206 turbine, soloy conversion. I always wore a chute and my door could be jettisoned by pulling one handle. Exactly for these kind of accidents.
I once had a chute deployed in the aircraft, but luckily the door was still closed, so it didn`t get sucked out. especially the reserve-chutes are easily deployed by accident. A good reason not to have safetybelts installed in jump-planes. It tangles up easily with chutes. But that`s illegal, although safe.