Did Joe West overrule Paul Schrieber Friday?

[Paul L]

It happened at the Washington/Cincinnati game last Friday, June 4. From Bill Ladson of MLB.com:

"The Nationals had just scored their fourth run of the game, as Willie Harris hit a sacrifice fly to drive in Roger Bernadina. At the same time, Ian Desmond tried to advance to third base and was ruled safe by third-base umpire Paul Schrieber.
Reds manager Dusty Baker came out of the dugout to argue that Desmond's foot was off the bag. Before Baker could say anything, first-base umpire Joe West told Baker that the umpires were going to talk it over.
"It looked like [Desmond] came off the bag to me," Baker said. "[Reds third baseman] Scottie [Rolen] is one of the best there is, and that's what I saw. Then they conferred, evidently somebody on the other side must have had a better vantage point than the third-base umpire did."
About 30 seconds later, West ruled that Desmond was out at third.
Desmond then tossed his helmet and West immediately ejected him from the game." (emphasis added.)

AP also reported that West, umping at first, overruled the third base umpire's call. I tried to tell my brothers that no ump, not even a crew chief, can overrule another umpire's call, and got laughed at for not accepting the facts. That it was Joe West, and that after the umpire conference he was the one who signaled the out, lent credibility to their claim. I have looked in vain on the internet for a definitive answer, but Schrieber looked to be in a good position to see the play.

Can anyone say for sure whether Schrieber asked for help or did West unilaterally inject himself into the call? And did Schrieber change his call after getting help from his fellow umps or did West actually overrule the call on his own?