She thinks being a cop is a job that can protect her. Girl, that is one of the most self-defeating ideas I have ever heard. Does she not realize cops are the ones putting themselves in danger?
We can all see where this is going, the unnie will keep making things worse until she finds out or figures out that the MC is the guy her friend pines over and she'll feel like total shit over her actions. That said, he shouldn't have assumed the lawyer girl was the one sending her secretary. Rather, he should have confronted her about it.