From AP:
"The issue was whether he had possession. The ball came loose when he was getting up. Pete Morelli determined it wasn't a catch," NFL spokesman Greg Aiello said. "That was his judgment."
In other words, the NFL is distancing themselves from the ruling while still keeping their options open when fining Joey Porter for stating that the refs were trying to influence the outcome of the game.
Porter was wrong to say what he did, but he was fired up right after the game. When you work that hard for something it's easy to make silly remarks.
BUT, the call was so universally panned by all the ex-professional players turned commentators on radio, TV, and in print, that it LOOKED LIKE A FIX. It was that bad.