The same would apply if you drove your car after 6 pints, if you arn't stopped there is no offence.
So, let's be clear about this - when someone is murdered, but the perp isn't caught, are you saying that there is no offence committed?
Or are you confusing the commiting of an offence with the reporting of an offence?
The latter means that someone got away with something, the former means that something "bad" was done. 119.5 therefore takes us to the axiom of the debate by asking about the ethics of a fictional situation, where someone suspected of doing something "bad" is allowed to continue their actions, by those accountable and responsible for protecting the passengers.
Thererfore, far from being a wind up, 119.5's question is worthy of consideration.
Let me make it quite clear that I am responding to your question about 119.5's fictional case study, not commenting on any alleged events at LBA.