You know, I have my doubts because of other aspects in that case, that really someone was after her. But that's right now not the point. The point is, if she was drugged, you could, provided, you can prove it in a court of law, pin someone for it. However, is she wasn't drugged but took the stuff voluntary, but it was someone else's, you can do that too, it's called "negligent manslaughter" (even it should be girlslaughter in this case). So, either way, if someone can figure out where they went to buy, and grill that guy, there could be maybe a hook to hang someone on.
JB's phone records might indicate which neighbor he went to met. Or a simple explanation...they could have driven down to the gate, let Pak in to follow them back to the house and got drugs or something else out of the SUV.