That roughing the passer call (nullifying a Pat's interception) is one of the reasons why the NFL is losing me. That wasn't a head shot: he hit him in the chest and his helmet brushed against the quarterback's chin. Horrible call.
Why don't they just play touch? Does the game really have to be ruined to protect the owners' investments in quarterbacks? Do the officials really need that much power over the outcome of games? That's what tempts guys like Donaghy to pollute the game.
Roughing the quarterback should only be called in cases of unnecessary roughness. And pass interference ought to be cut way, way back. What happened to allowing incidental contact? And I was always taught that the defensive back has just as much of a right to the ball as the receiver. If he makes contact with the receiver going for the ball, that should not be a foul.