Legal Commentary

So I'm taking a break from grading con law exams to watch my favorite team (the Mets) beat up on my least favorite local team (the Washington Don't-Call-Them-"Natinals"), and there was an odd play in tonight's game:

With no one out and Gary Sheffield on first base in the bottom of the sixth inning, Daniel Murphy hit a ball that appeared to glance off the facade of the second deck before landing in fair territory. On the field, the umpires ruled that it was in play (and so must not have hit the facade), and Sheffield was thrown out at home trying to score. After going to the video, the umpires overturned the call, and ruled it a two-run homer.  Murphy, who stopped at third, finished trotting around the bases, and the Mets took a 5-3 lead.

Here's my question, though:  What about Sheffield, who was thrown out at home before the replay?  Doesn't he have to go back and touch home at some point? If not, is it possible that I witnessed the first time (or, at least, one of the first times) in major league baseball history that a run "scored" without ever crossing home? 

I raise this because baseball's rules are notoriously formalistic when it comes to crossing home -- think back to Robin Ventura's "Grand Slam Single" in the 1999 NLCS.  So even if Murphy's shot is a homer, doesn't Sheffield have to cross home before his run can count?

Or is this just proof that technology will overcome even the most fundamental of all rule-based systems? Where are our jurisprudence scholars when we need them??