We had a situation on Sunday with the batsman running a leg bye and not playing a shot. interestingly, the umpire (paid) did us a favour when he called the ball dead as soon as two of our batsman had started off for a single. He should have declared dead ball only after the batsman had completed the run (obviously not counted as a run) or the ball had crossed the boundary. Would have been interesting to see the fielding sides reaction if they believed they had run the batsman out.
Dead ball should not be called in the instance as described above - if the bails had fallen off before the shot was played then yes, dead ball should have been the correct call.
Batsman given not out