Watch the replay again. Tony was holding Barbosa's arm as he was running away to get separation. Barbosa didn't push him down, Tony got tripped up on Barbosa's feet.
If you are going to argue that it was a foul against Barbosa, I'd strongly have to disagree.
The foul against Amare at the end of the half was atrocious as well. Duncan pulled him down, but because Duncan hit the ground first, it looked like he was the one fouled.
Overall, the officiating was HORRIBLE in this game for both teams. The refs let this game get way too physical. Duncan was getting hacked all over the place, and wasn't going to the line. Bowen was dry humping Nash all game long.
This was the worst officiated game of the playoffs so far, and not just because I am a Suns fan. I understand the refs wanting to just "let the players play, " but there was no excuse for this type of game.