IIRC in this scenario, there's a chance that the paratrooper can be pulled back into plane on certain conditions. One of them is that the paratrooper puts his hands behind his head to show that he is aware of the situation and that he isn't going to accidentally pull his chute. If he pulls his chute while they try reel him in, then he risks killing himself and others on the plane that are trying to pull him in. Hands behind the head show that he is not going anywhere near his chute and is waiting for action to be taken. I believe they have motors that can reel him in because like you said, no way people are reeling him in.

There are other conditions that must be met before any attempt to bring the stuck trooper in but I can't remember them. If the conditions do not permit them pulling the trooper in, then they will cut the line. They have secondary chutes I believe. Something happened to this guy because he was definitely conscious. Maybe no reserve, maybe his whole pack was fucked from the beginning.