How come I said the same thing 4 hours before and never got a LIKE or useful....?:Arghh: To get more likes or USEFUL awards...just copy what I said later in the thread.
my guess is. when he went to undo the wheel nut it was so tight he jammed a ratchet extension bar in-between your chain and back sprocket, then when he turned the nut again it moved the chain tensioning cam in the hub until the chain took up the last of the slack and the nut undid. not realising his mistake he just refitted the wheel and sent you on your way.