http://www.mlb.com/video/play.jsp?content_id=24853259&c_id=mlb
1) Both umpires are not in good positions.
2) The base umpire should be at 3rd base waiting for this play instead of still moving when the tag occurs in front of the base. He did not pre-plan well enough to be ahead of R2 as he was tagging up. He probably did not step up, turn and face the ball but instead, just turned and faced the ball and did not get deep enough into the working area and on the 3rd base side of it.
3) Joe West, the PU was not in line with the play. In umpire school they teach to line up the play at 3rd base with the plate and R3 approaching plus Joe had the tag up too but he never moved back after the tag-up to the point of the plate where he could more easily see the tag applied at 3rd and R3 approaching home.
4) Joe would have been better off if he stayed near the point of the plate instead of moving up the 3rd baseline some to see the tag up and the catch in left field. He is a very good umpire but again these plays happen so seldom that many umpires forget what they have been taught. He saw all he needed to see however to make the correct call.
5) They did not show how he sold that the run does not count but if they did show it, we should have seen Joe facing the press box and then signaling with waving arms above his head and saying, "No run scores! No run scores!