Money begets women. Good looking women. You can rightly question their morals and motives, but they show up for it. Any presumable drug dealer worth investigating would also have money and power to exercise one would think. When one with money and power and access to plenty of easy good looking throw-away women why are they messing around with.......this? Not that she is the Hunchback of Notre Dame or anything like that but she ain’t something to lose your head over either. Plenty of better looking women are passing out the sex, so, why even bother with it?
Like you, I am pretty sure she wasn’t his only piece.
First thing I would do if I headed an investigation would be to send her for a random drug test.