Each team has it’s own set of 12 footballs that it supplies. QB’s are particular in terms of how they are broken in. A new football has a coating of waxy plastic on it, for example.
Anyway, the only way one team would know about the ball thing is during a fumble or interception.
The ODD thing is that the refs ought to know too. During NE’s offensive series, the refs are in a position to figure this out, and perhaps didn’t.
There are an additional 12 backup footballs supplied by the home team in case either side runs out.
Aren’t the officials supposed to inspect the balls about 2 hours before the game?