That's what I thought at first too. But now I'm still in doubt.

Problem is that I sail single-handed and when encountering waves I have my focus not on the sheets.

I led my sheet already above the wishbone which makes it less sensitive for hits though the net. Besides that, you can see at the very end of the video that the sheet line from the wishbone to the camcleat is straight. So hitting the line with water will only move the line to go upwards.

And that's just the direction for fixing the sheet between the cams (it will unlock in downwards pull on the sheet).

I still don't know; you may be right afterall if there's nobody else with the same problem.

The last days I'm thinking of torsion of the hulls which will loosen the sheet on the sailside maybe a very short moment. And so make a free-ing more possible???????????