When is a cricket ball dead?

Question

I feel sure that I learned, decades ago, at school that the ball is dead "when the umpire deems it to be dead".

In other words the umpires at the Lords' test (including the third umpire), had every discretion to rule Bairstow "not out". He had, after all, been in his ground at the time the ball was taken by the wicket-keeper, and for reasons unconnected with play had left the crease.

The umpires' decision to give Bairstow out seems to me in total contradiction to the spirit of the laws of the game. Was it?

Answer 1

Law 20 "Dead Ball" is very clear on this.

20.1 Ball is dead

20.1.1 The ball becomes dead when [...] it is finally settled in the hands of the wicket-keeper or of the bowler.

[ some other things which don't apply here ]

20.1.2 The ball shall be considered to be dead when it is clear to the bowler’s end umpire that the fielding side and both batters at the wicket have ceased to regard it as in play.

20.2 Ball finally settled

Whether the ball is finally settled or not is a matter for the umpire alone to decide.

In this situation, it is clear that Alex Carey had not ceased to regard the ball as being in play, therefore the ball was not dead. That you or anyone else, including the umpires, think it impinges on the spirit of the game is honestly entirely irrelevant here, the ruling was absolutely correct within the laws.