Malfunctioning pressure gauge....
That is entirely possible and explains why the Refs didn’t catch it on inspection, why 11 out of 12 were under inflated and why only the Patriots side.
That said, after the Refs corrected it at the half, the Patriots put up 28 points and the Colts zippo. So if anything the Refs helped the Patriots.
Malfunctioning pressure gauge....
Not insignificant. Measuring the pressure will let some out.
“The next question is how did it happen?”
The balls were checked by officials just prior to the game. The deflating had to take place on the sidelines during the game. Can you say, ‘ball boys’? ;-)