I was nodding my head reading your post, but then I watched the video and it looks like this is not the case. He jumps out of the plane with someone else holding him, I’m not sure but it looks like this second person pulls his shoe off and lets it go maybe 30 metres below him, with the first person’s chute already deployed or deploying.
I guess then that a shoe has a relatively low terminal velocity. The skydiver seems pretty experienced, and it looks like he’s working his controls pretty hard to be able to fall as fast as the shoe.
