The day I encountered it I have no idea of what sensitivity controls might have existed but the problem was unquestionably the system failing to recognize that what had just transpired was a beat. The trace on the screen looked like a beat to me, but not always to it.

I will not say it was a management failure because I don't know if management could have done anything about it. Given the total indifference of the nurses I strongly suspect they couldn't do anything.