How about an uncalibrated pressure gage?
You're bringing a logical possibility to this discussion? The anti-Pats crowd will just claim that it was deliberately uncalibrated to get the desired result.
About time someone mentioned that.....
I play a lot of volleyball and have a digital gauge which is probably considered the best at around $30........
While all the volleyballs I have say to inflate to between 4.3 - 4.6 PSI, I could inflate a ball to 4.3, retest it 3 more times and get readings of between 3.8 and maybe 4.5....
The bottom line is, they're not precise, they're only modestly accurate and they can't be calibrated.