Front door release pins
That accident is a jump pilots worst nightmare and he did a great job.
With skydivers packed in the back and then getting up and stacking up for an exit it's pretty easy to catch a cable or pin but the guys and gals are very aware of that and it never happened to me in 6 yrs.
When I was flying skydivers I bought my own thin-back parachute and had it repacked and inspected at the required intervals at my own cost as sometimes a chute wasn't available for the pilot (this was 15 yrs ago)
What I don't understand is why jump planes don't have a front door jetison system like some aerobatic aircraft (a pull handle with wires that pulls the pin out of the door hinges) which immediately allows the pilot to roll out of the cockpit in an emergency
The fact he made it to the rear door with the aircraft in that attitude is amazing.