How do I decide the moment the wicket was broken on a run out or stumping?

Standard stumps and bails: the wicket is broken in the first frame in which one of the bails is shown (or can be deduced) to have lost all contact with the top of the stumps, provided the following frames show that bail permanently removed from the top of the stumps.

LED wickets (Zing bails and stumps): the wicket is broken in the first frame in which the LED lights come on, again provided the following frames show the bail permanently removed.

Compare that frame with the frame showing whether the batter's bat or person was grounded behind the popping crease.

On a referred stumping, bowled or hit wicket, first check the delivery was fair (any type of No ball on request, other than the feet, which you've already checked, and an illegal action). If the delivery wasn't fair, the batter is Not out and the on-field umpire signals No ball.

On any referred run out, bowled or hit wicket, if you find the batter is out by another mode (not LBW), or not out by any mode, tell the on-field umpire. Show red for Out and green for Not out, or use the replay screen in line with the Betway SA20 Big Screen Policy.