Ok, since I’m the person involved here (yes it is me in the picture) I take the liberty to join in the conversation. There is nothing either I or my jumper friend could have done up to this point, cause we simply had no clue this was happening. He found out just then, as I was presenting my left side to him. According to discussions we had with others after, what he did was the right thing to do: point to his own handle and point to mine. The problem is, as he was noticing my handle dangling, my audible sounded the break off point. So I waved off and prepared turning to track away. I didn’t see him point to his handle. I only saw him point to me or in the direction I was about to go. So my first reaction was, either he’s telling me where to go (which I thought was strange cause in the many jumps we’ve done together he’s never done that) or he’s telling me to look out for something in my line of flight. I couldn’t see anything. If my ditter hadn’t sounded yet, I probably would have figured it out.
To answer the initial question: how can we prevent that? When you move on the step, just be aware not to have your torso/belly right against the plane. Our plane fit up is good. There is a rounded PVC frame on the outside frame, with nothing protruding that can catch on. I was just too close to it when I moved back toward the center, and the angle of my handle was just perfect to displace itself out of its velcro pocket. A fabric handle would have been fine in this particular situation.