Brings back bad memories. Years ago I lost the pilot door on my RV-10. I was at the fuel pump when an Air National Guard C-130 that was park across the ramp from me, and pointed at me, decided to do a full power reveres thrust back taxi. The RV-10 was spun around and the pilot door (that was shut but not locked) was lifted and departed the airplane.
The door landed in the grass and had just one corner damage, but was fully servicable. The door however landed a corner on the top of the right wing and dented it. It too was fully airworthy. In the end (six months later) the Air National Guard paid for a replacement wing.
Looking at the photos I seems the hinge screws where pulled from the fiberglass. On my plane I used #10 tinnerman under the screw heads for any flush screw countersunk into fiberglass. For my incident the screws held but the hinge ears broke off. An overnight from Van’s of new hinges and the door was back. I suggest just countersinking those screws into fiberglass is not the way to go.
The experince also prompted a change to my POH. The cabin doors are alway shut and locked unless actively getting in or out of the plane, or if the plane is safely parked in the hangar. No exceptions. These doors are strong if properly locked, but very fragile otherwise.
As the photos show, both pins are out. As
only a guess this could be a repeat of the door being shut but only the foward pin engaged (as in the aft part of the door was not fully shut and the pin is on the outside of the door frame). The plane takes off and the door racks enough to pull out the forward pin - and the door departs the plane.
The Plane Around cam lock prevents the door being locked without both pins engaged. I consider this system mandatory on RV-10s.
https://planearound.com/shop/ols/products/new-door-180-kit
BTW - the old right wing is still in my hangar if anyone wants to come get it. No flaps, aileron or wingtip.
Carl