You can also see from the picture above that he didn't even stir when someone opposite actually rested on his foot. (Although he must have been oblivious to the fact that he was using someone else's foot as a ... err... footstool).
Sleeping guy spent the vast majority of the journey falling asleep on the men on either side of him. They tried to wake him up by giving massive shrugs of their shoulders, but Sleepy was out for the count. He'd sit up for a nano second and then fall asleep on the other guy. To his credit he gave them a bit of respite by occasionally lolling with his head back, so it hit the window a number of times. That didn't wake him up either.
I got off the Tube as normal, but wouldn't be surprised if the poor guy slept until Cockfosters. If ever there was a case for the "Wakemeupat" stickers, this was it. Although I have no idea what kind of shaking it would have taken to have woken him.