He's gone, 26-2
As to whether that ball hit Root's pad or bat first, the video must be at least AS inconclusive as the Agar stumping one, when they decided the principle of 'benefit of the (smallest) doubt' still applied. Inconsistent.
The umpire's decision was out. Nothing to change that. Was that the same with the Agar stumping?
Surely it just comes down to being sure enough to overrule the umpire, which in this case he clearly wasn't.
A stumping is an umpire review. No original decision to consider.