What are the potential risks and ethical considerations of a security guard relying on a heuristic that assumes all noises are harmless, given the low likelihood of robberies?

What are the potential risks and ethical implications of a security guard adopting a heuristic that dismisses all noises as harmless, given the improbability of robberies?

I wonder, why did you chose The Security guard problem for this?

Diligent guard is kinda effective as well no?