You aren't going to credit Gray for the offensive explosion are you? I will give more credit to the fact that Gronk was used as a sixth lineman blocking in the first half and they let him run routes in the second half. Add the fact that the Pats came out angry in the second half rather than sleep walking to through the game in the second half and the o-line did a much better blocking.
You are really stretching the argument if you think it was because of Gray. In fact, many of the big plays in the second half, Gray wasn't on the field.