I've had first aid training pretty much since I was 16 and currently hold FAW Certificate. I've had to deal with the usual fainting, splinters cuts etc with the cadets. The worst incident was an RTA in Germany when I was in the Army, when a Landrover with a British Army Driver and 3 American officers crashed into a lorry carrying eggs of all things. There was blood and eggs all over the show. I dealt with a chap (one of the American Officers who'd had his nose sheered from his face and was delirious, the hole in his face was about the size of a small tea plate and of course bleeding heavily. He wouldn't lay still and was ranting a fair bit. An experience I'll never forget.
While We were dealing with the accident a staff car pulled up to the scene, an American officer got out and went to the landrover wreckage and pulled out a briefcase, got back in the staff car and drove away. They didn't help at all, so there must have been something very very important in that briefcase !! Another memory of this incident was an arrogant German driver who refused to be diverted past the accident. He insisted on going past and told us we were not the police so wasn't going to pay attention to our instructions. We were just doing as we'd been trained to do and that was traffic control in the event of an accident, but that German guy wasn't playing the game. He was a very arrogant person.