I've been saying this for half-the week, the Colts arrived on a bus and their balls are in the luggage area that's probably unheated. They left the balls on the bus where they remained cold temperature, and any measurement in the referees locker room was too fast for the balls to adapt to the warm. Or, they were 12.5 outdoors and became 13.5 during measurement, then down to 12.5 (legal range) outside.
It's very simple to explain how the Colts balls could be within the right temperature the entire game while the Patriots dropped until more air was added half-way. Even though both started out valid both teams likely started at 12.5 (if the minimum is preferred by most quarterbacks if you believe the minimum) but the Colts balls were measured inside while they were cold and the Patriots while they were adapted to the indoors.
If the Giants played the Jets, that would be a different story as their game balls would be in the stadium the entire day before the game, so both team balls would be adapted to the indoors and would expect to lose a similar amount of pressure outside.
On top of this, the coating or pre-game ritual of the game balls can also affect the behavior of the leather and air pressure inside, even if both teams kept their balls inside all day.
Colts didn't cheat just like the Patriots didn't, but if the media wants to point out an unlikely chance of foul play, they should throw out ideas about the Colts and 30 other teams, too.