I think it's maybe because they are dead sure someone tampered, but they can't figure out how.
It's gotta be one of 3 things:
1. Weather
2. Refs' Laxity
3. Patriots Tampering
#3 seems the most likely BUT why in the world is this a mystery. If they tampered they should have it dead to rights.
Which brings us to #2. If the refs didn't even notice the deflated balls during the first half, how can we have any confidence in them at all?
The funny thing is that it could be #1 (as the BU professor explained). If the people saying the balls were 2 PSI under were using 13.5 as the baseline, the patriots balls could have been at 11.5 PSI. Many of us here read the original article that said the balls were at 11 PSI, which is only 1.5 under the threshold. If it was the weather, then this controversy will go on into perpetuity.