Bad enough to inadvertantly cause Brian Ong's DEATH, according to Wikipedia... although it doesn't sound like it was his fault:
"On May 28, 2001, Brian Ong volunteered to receive a flapjack from Singh. Singh did this move with two others in the gym that night, including one of the trainers, so Ong could see how it was done. Ong botched receiving the move, as he grabbed Singh's shirt instead of pushing off his back as the coaches had instructed him. He landed wrong and incurred a severe injury. Ong had suffered a previous concussion, and this second concussion ultimately proved fatal for him. As Singh inadvertently caused his death, Ong's family brought a lawsuit against All Pro Wrestling and were awarded damages of over $1.3 million."
Singh = Khali