It's a common occurance for the ref to check with an assistant on a grounding, and it makes sense as well.
That's exactly my point. He didn't check. The ref declared it held up. The TJ overruled him. Absolutely I'd expect it to go to the tmo, but if the ref thinks it's held up I'd say it's pretty usual to stick with his own infield decision.
Again, the live view was the TJ view. They used the refs view for the tmo replay. Presumably because the live TJ view was inconclusive.