Huh? If you are taking block outside of the crease you are fair game. It's why keepers come up to the stumps. It's usually why keepers try to throw the stumps down when keeping back, it's why in clode fielders often ping at the stumps, to try to catch the batsman off guard because he is "starting" outside the crease. It's pretty simple, if you start out of your crease you are inviting stumping and run out attempts. Bairstow did none of that. He was simply doing some gardening. It's a *smile* way to get a wicket IMO. Clearly most on here disagree.Marnus was batting out of his crease to try to counteract the English bowlers, most top batters do, he's not trying to "gain an advantage" he's trying to play the bowlers the best way he can. If he gets run out doing it, so be it, he'd deserve it for being dumb & not making sure he couldn't be dismissed that way.
Bairstow was dumb in not realising that he was in danger of such a dismissal.
A mate & I used to coach junior cricketers (many, many years ago) & we drummed into them to be vigilant about that exact thing. We told them, always keep some part of your foot or bat behind the crease line until the ball is returned to the bowler or the umpire calls "over"
The guy I was coaching with was a former District Cricketer, a good batsman made a lot of runs in that comp. He said that it was impressed on them to be wary of that particular type of dismissal.
Blah blah blah I was a cricket coach and I told juniors blah blah blah. He was a good district cricketer blah blah blah - what does that mean, he "knows" cricket? That's completely irrelevant.
Did you also teach them to sledge? Mankad?
I'd prefer the elite of sport set better examples. The game relies on camaraderie at the local level. At least it did when i played. These sort of incidents don't encourage that.