But therein lies the issue. You are reading something into the replay rule that isn't there. The replay rule only spells out that the review official gets to determine whether the call on the field is correct or not. That's a yes or no question. To that end, I think there is a major gap when it comes to spots, because the answer to the question "Where should the ball be spotted?" isn't yes or no.
There were two parts to this review:
1. Was the spot on the field correct? That could be answered with the visual evidence as a big "no". It was clearly incorrect. If this were a catch, or a fumble, or a foot in bounds, then the "no" would be the end of the review. That's also where the rulebook sort of ends.
2. Where should the ball have been spotted? There is no way that the review official could have been certain. But, despite giving the replay official authority over spots, it doesn't really deal with a situation where the spot on the field can easily be overturned, but the correct spot isn't clear. I'm sure you'll argue that it would naturally default back to the original spot even though that spot was already determined to be wrong. But the rulebook doesn't actually say that (at least not that I can find). The rulebook simply grants the review official the authority to overturn the original call on the field, which he did.
This may make a good argument for why spots shouldn't be reviewable at all, now that I look at it.