The argument should not be against running the non striker out and whether its within the spirit of the game. Warnings also should not be part of it since the rules don’t oblige you to do so.
Imo what you should look at is whether ashwin deliberately stopped in his delivery stride and waited for awhile till Buttler left the crease? Ashwin’s front foot also landed, so doesnt that mean he was at the point of release?
I saw this live. From what I can remember, Ashwin stopped and turned around. At this time Buttler was still in. Ashwin waited also for a split second and then took off the bails. On those grounds, I think its not out.
Watched the footage again. Maybe Ashwin deliberately was not waiting for Buttler to leave the crease? Because when he looked at Buttler he was already out of the crease? IDK but still I think you can fairly say by the time his left foot lands, he has reached the point of “ expected to release the ball” as the law says. Its very tricky and its not out imo. Ashwin should probably be given a bit of a break from everyone calling for his head. But its still not out imo. Third umpire only checked whether he’s out of the crease that is all.