Just my opinion, I guess, but it appears pretty obvious to me that Tomlinson's left foot is at the 26, but his arm is reaching back toward the 25 - it is not where Tomlinson is but which direction the ball travels. From the 25 1/2 where the ball is released from his hand to the the 26 where Chambers catches it is a forward pass.
Sounds like the ref that reviewed the play confused the other refs - they thought he meant the second exchange was forward - since the ball hit the ground after that exchange, they convinced him to rule the play dead (since any forward pass, legal or illegal, that is incomplete results in a dead ball). In fact, it was the first exchange that was a forward pass - and was completed - therefore the play should have continued and the TD should have counted.
Here's the article, although it makes about as much sense as the call....http://sports.espn.go.com/nfl/news/story?id=3707245