The person who raises a false alarm may be punished more visibly than the system that made certainty impossible.

The person who raises a false alarm gets a visible consequence, and the conditions that made certainty impossible get none. Punishing the individual is easy and immediate; fixing an environment where nobody could tell is slow and expensive. So the sanction lands where it can, and everyone learns to stay quiet.

If you have any influence over how these things are handled, protect the honest false alarm explicitly. The alternative is silence about real ones, which costs far more. And if you have been embarrassed by raising something that turned out to be nothing, that is the correct behaviour under uncertainty, whatever the reaction suggested.