Not sure if that was quick thinking of the P1 to unlatch the door following the collision (in case the frame bent and jammed the door), or maybe the rapid swing round un popping the latch/flinging an open door outwards. If deliberate then that's pretty quick reactions from the pilot.
Also right rudder into the turn - seems counter intuitive but maybe trying to avoid a stall, the jolt caused P1 to step on the right pedal or deliberately trying to shed the canopy from the wing.
Anyhow great to see both walked away from this. In the end we're all up there for pretty much the same reasons and too often these accidents don't end so well.