It's not so hard to get from A to B in any public show: The trick is just to act like you belong there, just like everyone else who also belongs there. Blend in.
My own favorite was at a show at the Detroit State Theater. We had assigned seats in the balcony, but the sound really was very bad up there. So we left, wandered, and came up to the entrance for the general-admittance floor area.
There were two security guards looking at tickets before people were allowed into this space, with a small line formed before each of them. We walked right between them as if we owned the venue ourselves, and didn't encounter any trouble. (The sound at front, stage-left was excellent. Kudos to the boardmonkey, and meh to whoever it was that specified the line arrays for that show.)
And for other intermittently-crowded places, carrying a Motorola 2-way portable radio helps. You can direct traffic and behave authoritatively in almost any capacity, even with long hair, regular clothes, and a beard, as long as you have a radio and the gumption to make it look like you belong there. Do that for a little bit, and nobody around will think twice when you slip in through a side door. And after that, just blend in differently: At that level, people aren't paying much attention to security.
(And no, it doesn't matter if the radio works or can talk to anyone.)
So: Social engineering one's way into the Superbowl? Nice feat, but not very surprising.