What Caine from Kung Fu died of.
Caine started jerking off, then put the bolito around his own neck just before he was about to get off to see if it would be more intense, and ended up losing part of the hand he jerked off with trying to keep the wire from slicing his carotid artery and jugular vein, along with his head eventually, before the bolito stopped. It might have been a different kind of intense experience for him. He was the first person to ever try the autoerotic bolito, and was actually successful in the sense that the bolito did what it was supposed to do.