I agree with the implication, but don't think this applies here. The scenario here is a safety net, i.e. something that visibly "catches" errors, at a cost. If you have zero incidents "caught" during the evaluation period, then the evaluation result is that the cost isn't worth paying.

Obviously if you're planning to implement a vague deterrent-style solution which you have no means (or intent) of evaluating just to check a box, you're better off not doing it.