Matthew. The ball has to break the plane. Look it up in The NFL rule book. And yes it was a bad call. I hope that ref gets fined big time. But, it doesn't make the Steelers cheaters. That much is true. As for the ref, his explanation of the overturned call didn't involve the football in any way which is just wierd. He needs to learn the rules.
Edit*
According to the official NFL Rulebook, a touchdown occurs "when any part of the ball, legally in possession of a player inbounds, breaks the plane of the opponent's goal line, provided it is not a touchback." The ball, in this case, didn't cross the plane of the opponent's goal line. There is also an excellent picture where the ball was CLEARLY not over the goal line.
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