Not impossible at all. I've had it happen twice! The first time was a flight to around 50K. The fin can separated from the harness when the main came out. I never knew why it happened. The second time was on a flight to around 14K as I recall. When we got to the rocket, no fin can - where have I seen this before? We looked around and there was the fin can about 100 feet away, separated again when the main came out. The second flight was on video. It doesn't show the quicklink opening, but it shows the spinning quite well. Now, I use a swivel and tape the quicklinks (or just use an old quicklink that won't easily open). This isn't a one-in-a-million thing - it's much more likely to happen then that.Amazing video. I would have thought this was impossible.