To me it looks like the guy is gonna bleed to death, it looks like he put his thighs on the track ?
Oh well, fuck it if you gotta go you gotta go.
Most Tube type trains run a thin Wheel base. By laying himself as he did he would successfully cut his head at the shoulders and his legs at about the thighs. The main abdomen of the body would then be dragged down the tracks. Confirming death.
look at that short fat guy. he saw the whole and in the end, he was still going to board the train as if nothing happened.
He went straight to the doors that would be where the kid jumped. There are parts of the floors on trains that can open to get below. I am thinking this is what he was doing...maybe he was shocked?
Feel bad for the guy with the back pack who rushed forward too late to do something. He's gonna live with that memory for the rest of his life poor sod.