Pranks seem funny when one is young, stupid as one gets older, I am no Angel, and when I spied some one had wired an impulse mag to the vice on a work bench it was just asking for some one to turn the table.
So I wandered to the bench and rested one hand on the vice, sure enough the guy strolls up and starts to talk to me. As I saw his hand go to the mag I put my other hands fingers on the back of his neck.
The guy dropped to the floor with no sign of life. I really thought I had killed him, then he slowly recovered, I was so relieved, everyone else thought I was great giving the guy a taste of his own medicine, however I realised how lucky I was not to have killed him.
Be it poor heart, or any other medical problem, it is so easy for these jokes to go wrong. Often something we never considered, nearly every accident is a combination of a few items, not one single action, otherwise not really an accident.
All it needs is one arms binding to fail, and the lad has a broken arm. It is a stupid prank, I am sure HSE would take a very dim view, and to video it, they clearly want to get caught,