As I've stated before (even when I was defending them), the measurements don't make sense. PFT had an article on the strange inaccuracies of the gauges used:
http://profootballtalk.nbcsports.com/2015/05/10/pressure-gauge-discrepancies-undermine-wells-report/
The issue here is NOT the measurements (which are confusing as hell and don't make a lick of sense).
What is the smoking gun is the text messages and the amount of conversation Brady had with the ball boys immediately after the story broke. The fact they specifically talk about a "needle" and using said needle to alter the balls after the referee's inspection and/or during the games is illegal. Plain and simple.
I have long defended that a team can tell the refs prior to the game "we want the balls at 12.5 psi" (low end of the scale). And I would even defend a few coming a tick or two under when turning the balls over to the referees and telling them "If any are low, just pump them up to 12.5".
And what happens after that due to nature is fine (and many, many times in cold weather the balls will drop way below 12.5 psi).
But it did not happen to the Balls the colts were using so that argument does not have any merit at all, unless the weather was radically different on the other side of the field.
What is clearly illegal and what should be severely punished is letting air out of the balls. That is a HUGE no-no in my book and should be strongly punished. I could care less why or how the Patriots were caught. I could care less how many other teams are doing it (and I'm sure many are/were). The point now is the Patriots got caught and that they are a repeat offender of bending/breaking the rules.
Again:
Patriots/Kraft: fined $5 million
Belichick: fined $500,000.00
Patriots Team: Sacrifice 2016 first round pick
Brady: suspended 2 games
Ball Boys: banned for life