He is very particular about exactly how he likes his footballs so he would certainly know when choosing them out anything is wrong. Yet the entire time he was playing he had no idea they were different. Is one example
weak. Many people are experimenting and trying to feel the difference of 2 pounds psi, and they're saying it don't feel that much different.
Do you realize the amount of focus and concentration a QB has to have from the snap to the pass?
He has to see the last second changes of the defense, see where the pressure is coming from, look at his WRs, find one that will be open by the time his pass gets to them, etc. etc. I believe that it is very possible that he wouldn't notice the difference. (Only people with amazing ability to focus in can be NFL QBs, we can't even begin to understand the powers they have of blanking out everything except for their job at hand)