Watching the replay and hearing Busch's spotter, I think it's really the spotter's fault. He said something to the effect of, "coming high", implying that Tony had a run on him but wasn't there yet. He clearly had a fender along side at that time. If a car is already next to you, the spotter should be saying something like "car high."
It would have been interesting to see what would have happened had they stayed side-by-side to the finish.