Don’t worry too much about stumbling. I think they’re more lenient if it’s an accident. Well, worry about your own safety, as a train to the face can really put a damper on your day.
I think the 10 minute delays are only when the jumper survives the impact (it happens) or is thrown completely clear of the tracks. In cases of survivors, the person is moved from the tracks, medical help is called, rudimentary cleanup is done on the train, and everything starts running as before.
If the jumper dies, however, it’s another story. The body can’t be moved until the police arrive and survey the scene, so if it’s still on the tracks, nobody’s going anywhere for at least half an hour. On a morning rush-hour train, there can be over 3,000 people in one train, plus every train behind it is also stopped, so a lot of people are stuck in a very uncomfortable situation (you’ve heard the horror stories of people packed into the trains like play-doh? they’re true) for much longer than they want to be, which can be a health risk in itself.
There was one of these Sunday morning as I was going to wedding. I didn’t see the actual accident (but I was in the front car and heard the impact), but it seemed to be someone who was standing too close to the edge and got clipped (really early in the morning, so probably somone who’d been out drinking and was falling asleep on his feet.) I don’t know if s/he got hit in the head or shoulder, but after the station staff finished checking his condition and getting help, two of them walked to the front of the train and started inspecting for damage or blood. We left the station after about 10 minutes, and the front of the train looked clean when I got to my destination. No hoses were used, although they may have done some wiping with a handkerchief.
There was no mention of it in the paper the next day, so he probably survived. If so, he was lucky. There was a bad accident last year in which three people were struck and killed (one drunk guy who had fallen, and two others who had been trying to pull him out of the way, none of them were fined, AFAIK). Those trains move fast.