I think a lot of folks (not only on this thread, but elsewhere in the sports media world) are thinking everything happened in nice little discrete events, within a very short period of time, which further reinforces the notion of bad intent...or willful cheating.
I'd first like to cite the comments of Aaron Rodgers, who suggested that he typically "gets away" with over-inflated balls, which happens to be his preference. According to Aaron, however, there have been a few cases where the refs have caught the "indiscretion", and released air from the balls to get them within spec (12.5 - 13.5 psi). And no cheating was ever accused in these cases.
We've also heard that both Peyton and Eli Manning have advocated to the NFL (for quite some time) that they be allowed to have their own pre-conditioned footballs...footballs that they evidently use throughout the entire season (I'm guessing that his could even include the pre-season as well). These footballs are "groomed" over the course of a very long time (months, at least) and ultimately attain (again, over time) the desired characteristics that each QB individually prefers. The NFL has sanctioned this practice, evidently, with Peyton having been one of the chief advocates (this according to Rogers).
So it's my belief that:
1) Over the course of a season, the balls naturally lose a small amount of pressure, and they are not routinely pumped up - i.e. on a daily basis, as many people seem to believe. The theory being "if it ain't broke, don't fix it"....or, if the QB is happy with it, don't mess with it.
2) At game-time, the referees give lip service to the inspection, opting to use their sense of touch/feel vs an actual psi gauge on 12 or more footballs to assess each ball's individual pressure spec (again, this is my guess...and it could also be the reason why the NFL is now "very disappointed" because this check has not been rigorously/uniformly conducted).
3) All Teams know this...and present their footballs "as is" for the inspection, whether overly inflated like the Packers, or slightly underinflated like the Patriots (or maybe several other teams?). The idea here is that it's "on the referees" to determine the suitability of the balls...not the team itself.
4) Both BB and TB are well aware of this phenomenon, just like Aaron Rogers and the Packers are, so I guess you could say that they are all "complicit". However I'm guessing they would never stand in the way of a finding whereby a ball (or balls) needed to be inflated to a higher psi, if so determined. Yet they'd certainly accept the use of the balls "as is" because it's already been determined (in all those previous practices and games) that they are perfectly aligned to the preference of the QB who will be handling and/or throwing them during the game.
5) So does this constitute cheating?
6) OTOH, any evidence which demonstrates...conclusively...that the balls were altered after the referee's inspection, by a member of the Patriots, and/or at the direction of the Patriots, would indicate cheating.
7) I think the environmental conditions, and the dynamic nature of those conditions (temperature, humidity, atmospheric pressure, etc.) played a very minor part in this whole situation. Reason being that the balls were probably never measured at 40 degrees F (game conditions). They were likely measured at around 70 degrees F (indoor/room temperature conditions). So any pressure losses attributable to a 30 degree temp differential would never come into play in any of these determinations, nor would they be meaningful either.