I've seen it 3 times in multiplayer where a slammer or something is airlifted to another location is dropped on the ground and then after it is released it will be floating in mid air.
If you can get close enough to get into the vehicle and jump in the vehicle will respawn with you in it back to the original location it was picked up.
Got a repro? I'm 99% sure there's something wrong with the script, and not with the game.
You know I don't know if this is something that is built into the game or if it is a server mod. I tried again last night and there were some bugs to it. Like I was able to lift it without even lowering the rope once and I wasn't near it and nothing showed up when I was lifting it. Then I dropped it and it spawned somewhere else. So its definitely something odd. I just don't know if this is a feature of the game or something someone made.
Like I said: got a repro? Go to your local files, find the mission pbo and attach it to this ticket. Until the devs know what the script did exactly, I doubt they will ever find any bugs...
Upvoted, there something similar happens with falling units, they get raised over ground after falling down if still alive.
possibly related: http://feedback.arma3.com/view.php?id=15167