Time or Space: which is more important?

In tonight's Broncos v. Texans game (which I saw because I get the NFL Network), Broncos CB Dre Bly intercepted a tipped Sage Rosenfels pass in the 3rd quarter that led to a Denver TD that cut the Texans' lead to 17-13.

On the play, an official threw a flag for pass interference, which would have nullified the interception. However, on the play, a Denver defender underneath the Houston receiver tipped the ball, causing it to go over the receiver and the defender who was interfering with the receiver into Dre Bly's arms. The officials decided to pick up the flag because they said the tip occurred before the defender made contact with the receiver.

Replays clearly showed that the defender made contact with the receiver before the ball was tipped. So, in time, it was pass interference. (Note: I know replay isn't allowed on pass interference ... I'm just saying I saw replays and they clearly showed this.)

On the other hand, the ball was tipped before it got to the receiver. In fact, the ball was tipped in such a manner that the ball wasn't catchable for the receiver. So, in the space world, it wasn't pass interference because of the tip and the uncatchable nature of the ball.

By rule, I think the officials got it wrong. I think that because the PI occurred (in time) before the ball was tipped, the guy who threw the flag was right on. However, I think the officials got it right if you are not going by the letter of the law, but rather by the spirit of the rule. The pass interference had no impact on the play. If there hadn't been a guy interfering with the receiver, Bly still would have had the opportunity to make the interception. I'm just wondering what grade the officials will get when they are reviewed. Maybe the officials involved will fill us in.