Why was that umpire's decision rather than not out? Hit outside the line so it's not out. Going by the DRS if the in-field umpire gave it out, that would have stood.
No, its just that their graphic continues regardless of if it cannot be out, unlike how 9 do it here.
It was pitch outside off, hit outside the line (not out), umpires call on hitting the stumps. It says each of the 3 things, and they all must be satisfied for it to be out.