LBR... that's certainly a unique point of view, and one that didn't occur to me.
I honestly don't know for sure that the pitcher remained in the circle with the ball in hand as long as it took for BR to touch first, "round" the base, stop (in line), and not proceed toward a base. Something I could watch for next time this happens (if ever it does).
And I suppose LBR on the BR, if it occurred prior to R1 on 3B touching home (which this one never did) would nullify the run, just as an out on a runner overrunning a base would nullify a run on a slow moving R1. Interesting. (I think I'd feel like supreme OOO for making this call, by the way!)
OK - let's say she didn't. Either BR stayed at 1st, or pitcher was not holding the ball... I'm not sure I like Mike's solution, especially if this was a game that mattered, although I do admire it's elegance, and appreciate that in this case you're making a no-call where no-call was expected.
Needless to say, this whole sitch troubles me.