I have worked on a show where the SM would miss 30-40% of called cues - this wasn't a small show either, it was an
IATSE touring Broadway musical. The SM lasted 13 performances before they had a replacement out to us. We noticed she was bad fairly quickly and we would all take the cues ourself -- including our flyman who had the potential to
deck actors if he didn't watch out really good. The entire crew held a meeting to see what we should do about it - we had run the show 100+ times and could do it ourselves by then. We decided to give her a week to see if she improved, and after the first week we told her we were taking cues where she called them. 4 actors were decked, the light cues got almost a full song off at one moment - we had a ton of
midi linked cues where LX would fire sounds, it was a disaster.
Long story short: I almost always take the
cue if SM forgets because my cues are not
safety dependent most of the time (sound here...). If my cues have the ability to hurt other people I'll skip it - usually there isn't enough time to ask for clarification. I'm the sound engineer on a Local 1/
AEA show at the moment and I have had SM's miss the 2 called cues they give me (I take about a hundred others myself) once in a while - they have to
call 800 other cues an act, and when we have an SM who hasn't called in a few weeks mistakes can happen. I take those missed cues every time because I know they don't impact the
safety of the scene but do further the story (1 of them will not cause the entire scene to progress...) and without them we wouldn't have a viable show.
to wrap it up: time and place, if it's appropriate take it.