But the 2000lb elephant in the room that no one wants to talk about is still this: Those footballs were examined and passed for play by the officials. They were in the official's care until just before the start of the game, when they were given to the team's ball boy(s) and placed in a large blue bag. The ONLY persons who could access those balls were the ball boy(s) and the refs.
There are cameras all over Gillette. Besides the ones used to film the game, and the broadcast ones, there are security cameras watching all of the sidelines, the end zones, the tunnels, the stands, etc. There are probably more cameras there than in a casino. How anyone could possibly tamper with those footballs is beyond me.
At halftime, those footballs remain in the possession of the ball boys and on the sidelines. They don't come in with the rest of the team. If the equipment manager came over with a pressure gauge and a needle and started to uniformly remove air pressure by 2psi, SOMEONE would have noticed. There are still scads of reporters in the booths who would see it. Security people who would see it, etc.
So deflating the balls at halftime isn't likely to have happened.
The only thing left is that the officials accepted the balls prior to the game with a reduced pressure and failed to inspect any of them. It's the only thing that makes any sense at all.