aqn said:
A tire is like a balloon: it's easier to squish an underinflated balloon. Overinflation probably helps a tire resist deformation (at the expense of comfort, and possibly more wear in the center of the tread).
Also just out of curiosity, what kind of damage does a pothole typically do to a tire? I would assume the damage is done after the tire enters the pothole, and as it encounters the sharp edge trying to leave it. Is it a matter of pinching and tearing the sidewall, or does it actually slice through the belts under the tread? If you will pardon the pun, I could see your explanation cutting both ways. Sidewall failure would seem more likely at a low pressure, but tread failure would seem more likely at a high pressure, since the tire can't deform as much to absorb the energy.
Ray