That's nonsense. Harassment is when the other party doesn't agree to it. And the MC didn't. Technically she didn't do it the first time, but only because the MC objected to it, i.e. she didn't want it. Second time she just jumped her out of nowhere, with her dick right in the MC's face. So it gets hard to look away. And the MC didn't react positively. In addition if the cop's cock touched the MC, she could have sued her for sexual assault. So the cop got lucky.
Correction, only Rachel begged her, because she didn't want to go to jail or pay a fine, not knowing the cop and thus that the alternative could be worse.
The cop should have taken them in or fined them. If the cop doesn't hand over the confiscated drugs at a police station, she herself would be guilty of drug possession. If she truly wanted to helped them, she would have looked away and she didn't.
Bottom line: the cop doesn't have a moral high ground, because of hidden intentions. She never wanted to help out of the goodness of her heart.