As has been well-documented elsewhere (here, for one), the officiating in this year's NFL playoffs has been pretty poor. I'm watching the Steelers-Broncos game right now, and the Steelers just had a Jerome Bettis touchdown called back on an illegal formation penalty. The official said that Hines Ward lined up on the line of scrimmage outside the tight end, so the formation was illegal. That's just a bad call.
Here's what the NFL rulebook has to say: "Offensive team must have at least seven players on line." AT LEAST seven players. There's nothing barring them from having eight players on the line of scrimmage, as the Steelers did on the Bettis touchdown.
The only problem with "covering" the tight end is that the TE is no longer an eilgible receiver on that play. (Rulebook again: "Eligible receivers on the offensive team are players on either end of line (other than center, guard, or tackle) or players at least one yard behind the line at the snap.") But the touchdown came on a running play - whether you're an eligible receiver is irrelevant.
That is a horrible call. Fortunately, the Steelers scored another touchdown immediately thereafter, so the refs are off the hook. I'm curious to see if we can get a Joey Porter quote out of this...