Wow, this might be the first time we've ever seen anything like this one! These skydivers were attempting to put together a 10-way belly jump from two Cessna 206's. As one of the jumpers climbed out, he sat on the wing strut to give everyone else more room to set up in the door. In that moment, his d-bag popped out of the container and wrapped around the strut!
Fortunately his pilot chute remained in the BOC and he was able to pull the d-bag back up over the strut and exit without damaging the plane (or injuring the other jumpers). We were told that he worked out a snag during freefall and didn't deploy his pilot chute until 4,500 feet, but apparently it opened without any issue and he landed "uneventfully" on his main canopy.
When five people cram into a Cessna 206, they're going to be really up close and personal with one another (don't make matters worse without deodorant). Those tight conditions mean that there's always going to be some degree of rubbing up on something — either against another jumper or the plane. The video doesn't show this clearly, partially because of the cramped circumstances and partially because the sun is right behind the jumper in question, but we are guessing that as the jumper attempted to climb out and sit on the strut, he rubbed up against the door frame and dislodged the flap protecting their main pin, and then the pin itself too.
Like we said above, in these types of circumstances, rubbing against one another and the plane is pretty much unavoidable. However, just because something is inevitable doesn't mean that we don't take steps to minimize potential/foreseeable consequences. We all know that door frames are one of the most dangerous hard surfaces which can pop a flap, a pin, or a handle. If you know you're in a slot which requires you to come close to the door frame, take the extra half second to ensure that you're not rubbing your container up against it as you exit.
This jumper reportedly had just over one hundred jumps. If that's the case then he did a pretty good job reacting quickly, realizing that he needed to grab that bag, bring it around the wing strut, and get the heck away from everyone else. Some folks may argue that he should have tried to get back into the plane, but had his pilot chute come out while he was doing that it would have turned a relatively minor issue into one which could have killed him and maybe even brought the plane down.