While this has been discussed in other threads, for those that still believe in him, DON'T. Those "innocent" bystanders are paid actors. Any "happenstance" where he does anything with any innocent bystander is pure bullshit, they are all paid to be there.
Whenever you see one of his stunts he is basically filming a skit where everyone has lines to say, where to look, how to act, etc. It is all rehearsed. Everyone you see on camera is part of the cast.
There is more info on the previous threads, do a search and read up on him there.
As for him stopping his heart: I can stop my heart and have 500 "nurses" witness it, as long as I paid them to say: there's no pulse, there's no pulse on cue. If you believe that those were real nurses, and weren't in on it, you also must believe that Tobie MaGuire can shoot spider webs out of his wrists and swing through the streets of New York.