This was a story told to me by a visiting med student, about someone in his class who actually got kicked out of school. Just in case you were wondering what it takes:
The student was on his surgery rotation and was scrubbed in to a surgery with the chief of surgery. Somehow, he got contaminated.
Now staying sterile during a surgery is one of those mysterious things where you can touch one thing that seems disgusting (like bowel) and still be sterile, but you touch your chin and now you're contaminated. So you have to be very careful and a lot of the time you end up getting contaminated and sent out of the room to rescrub for reasons that you don't quite understand.
Anyway, the chief of surgery said to the med student: "You're contaminated. Go outside and rescrub."
The student replied, "No, I'm not."
Chief of Surgery: "Yes. You are."
Med student: "No, I'm not."
Chief of Surgery: "Yes, you are. Look, it's not a big deal. Just go outside, rescrub, then come back in."
Med student: "But I'm not contaminated. I'll prove it."
Then the med student proceeded to touch every single one of the sterile surgical instruments, and then stuck his hand into the patient's open body cavity in order to "prove" that he was still sterile. Although even if he had been sterile, I'm not sure what proof that provided other than proof that he was insane.
So in case you were wondering, that's what it takes to get kicked out of med school.