The ball air pressure should be 12.5 to 13.5 PSI.
If the pressure was measured in a 72 F room, then the balls were brought to a cold football field at approximately 32 F, the pressure of the balls all fall by approximately 1 PSI due to the temperature change. So, all the balls should be under pressure unless the refs were doing their job and inflating the balls back to the appropriate pressure range.
The math:
Air pressure is proportional to temperature in Kelvin.
72 F = 295.4 K
32 F = 273.2 K
percent change in pressure = (295.4-273.2)/295.4 x 100= 7.5%
A ball at pressure 13.5 PSI will drop 13.5 x .075= 1.01 PSI; the pressure will be less than 12.5.
Likewise, a ball at 12.5 PSI will drop 12.5 x .075=0.94; the pressure will be less than 12.5.
I hope the commissioner knows how to read and do math. I also hope he doesn't destroy evidence like he did the last time.