Deflategate and the subsequent witch hunt by the league was about getting Brady and making an example of him. The union agreed to let Goodell have absolute power to do whatever he saw fit. He saw fit to suspend Brady because 1) he could. By taking down arguably the biggest star of the league, he showed the rank and file that no one was immune to his kangaroo courts. 2) Brady laughed that the Ravens should know the rules better in a presser and they dropped the dime to the Colts. It was an opportunity to try to get even with Brady and the Colts were more than keen on being a narc in an effort to get Brady off the field, since they already had a track record of trying to beat the Pats off the field with the whole rule change thing and ... 3) It was in retaliation for Brady putting his name on the concussion lawsuit.
The league never gave two chits about the PSI, that was all doctored up BS for TV. No doubt their findings exonerated Brady, otherwise they would have shown them and made themselves look better. They all but confirmed that by not showing their findings. Everyone knows air pressure goes down when it's cold. Every winter, your TPMS light comes on, yes? There you go.