Ok, so what if this is what happened: BB and Brady both see that Moss is continually drawing double coverage and it's taking him out of the play most of the time. Bonus is that Welker is getting open all over the place. So, on the sidelines while the D is on the field, they tell Randy, "Look, we know it's going to be tough to get you the ball tonight, but just keep going through your routes and as long as you're drawing 2 defenders we're in business." I wouldn't hold anything against Moss for running at 80% as long as it continues to keep 2 defenders off of the rest of the receivers. So, what might have appeared to Jaws as "dogging it" was simply the way they knew things were going to go the rest of the game.
They won....end of story.