Well, to sum it up this way….
If the moment that person says they are 14, you run away quickly, then the police have no crime to investigate. The cry of entrapment never comes from the person who didn’t do anything to be entrapped by.
As far as you calling them out, good for you. I do kind of a similar thing, in that when I am talking to someone that then suddenly tells me they are underage, I report them to the app, then block them.
And I definitely did not say that they cops were right in doing this. I also think it is a despicable practice done in the name of catching them there perverts (sound of a spittoon) but again, if the conversation is stopped the moment the age is mentioned, then the cops have nothing to go on.