Well supposedly the majority of the 11/12 were just a few ticks under 12.5 meaning somewhere in the 12-12.4 range suggesting weather as the reason as BB and thousands of scientists concluded (except Bill Nye who is dumber than Goodell). The one ball of that 11 that was significantly under inflated (by roughly 2psi) was the ball that was intercepted by D'Qwell "pizza boy killer" Jackson.
Here's where it gets interesting. Troy Vincent has already confirmed Ryan Grigson, the Colts GM was the Eric Mangini or the Rat, leaving him helpless to deny blame so we have the guy. It is entirely possible he was hoping to create a firestorm/screw the Pats and ordered the ball deflated anticipating others to be similar. This isn't exactly a far-fetched scenario because we know what lengths Colts GM's will go to in accusations against the Pats.
But yes, in short, really only one ball was significantly under inflated which basically puts that stupid Mortensen report to shame.