Another factor to consider. A football is not a fixed size vessel. It is a rubber bladder inside leather. There is an amount of elasticity that would help maintain pressure when the gas loses some volume do to cooling.
I’ve studied thus a bit. I can’t find any language in rule two that requires the pressure to be maintained after the test. It is only implied. I’m not sure the rule doesn’t preclude deflation to a desired pressure. It only says the ref need remove non spec balls. Even if the Pats deflated the balls they probably are in compliance with rule two.