Continuing the umpire discussion

I received a great deal of e-mail about Bob Davidson's blown call in Sunday's U.S.-Japan game, and wanted to share a sampling with you:

Bob T.: Rob, I wonder if you could ever use instant replay with any authority on a tag-up play. I know we see split screens and they say "these are synchronized." But are they really? We just take it on faith that TV producers with all their fancy gizmos have everything synched up.

But I really doubt that perfect synchronization for that sort of play is possible. I even think of the example that if I am watching a game on my bedroom TV (with analog cable) and then have it on the living room TV (with digital cable) that the digital cable runs a few seconds behind the analog cable because the digital cable is hooked up to more things and the signal has to take a longer route.