OK, here's an interesting scenario -- supposing the original call on something like this was that it hit the wall and therefore not a HR. But the replay rules that not only did it not hit the back wall but that it never hit any wall at all but just Crisp's glove and that Crisp caught it on the way down (he didn't, but just play along for the moment). Does the video then allow the umps to change the call to an out even though it's only supposed to be used for boundary calls not out/safe calls? Yes, a replay can be used to turn a call to an out, but can only do so on balls that are initially called as home runs but that fans interfered with. I can't ever see your scenario actually happening. It would require a ball initially being called "in play, not a homer" but actually having been caught. It would require a colossal screw-up for an umpire to miss the ball actually being caught in that scenario. (A play initially called "out" is not replay reviewable). If they ever really did screw that up so badly, I do think they can overrule the call after conferring (but not with the benefit of replay). I agree it would need to be an unusual situation: something on the order of the umps initially calling that the ball hit the fence and then fell into the OF's glove only to discover that it hit his glove in front of the wall and then fell into his glove. Bay's drive last night did, in fact, appear to hit only Crisp's glove and not either the front or back walls but of course he did not cradle the rebound. But as I was watching things unfold last night the thought occurred to me that Terry could come out an argue for a review only to have the call wind up worse for his team than the one they originally made (triple turned into an out rather than the hoped-for HR) and more generally about the slippery slope you get into when you decide to employ replay but only for limited uses. IOW, what if you go looking for something but then find something else that's not specifically under the replay guidelines? In this case the rule, which is in place only be used for HR questions, would overturn a catch/no-catch call simply because that was near the wall where a similar out/safe question where the OFer is coming in could not be settled via replay. And, btw, what would you do with any runner(s) in the above (or similar) hypothetical? Naturally they see the safe call and run. Can they now be blamed for not retreating even though they were following the ump's call at the time? Do you place them back at their bases free of charge so to speak because the wrong call was made? Is it a judgement call as to whether or not they could have made it back based on where they were at the time of the call, a ruling which could place some runners back on their base of origin but others not?