@MimosaMornings, I think it's been reported that the ex lived in another building and not the one she was on video at.
One very close by and if I remember correctly even on the same block.
If that's true then I'm thinking they were probably at his place for whatever reason (argue/talk/make-up), she was probably drugged sometime while at his place, she then left (possibly left before the drugs took effect?), then came back once she realized something was wrong, parked haphazardly at the wrong building possibly thinking it looked somewhat similar to the ex's place.
After that point is still the mystery.