I remember Misty stating to her father in a jail house tape that their family wasn't so innocent (meaning cummings family), she said every last one of em was into dope. I understaood that to mean TN and RC and whoever else was in TNs world. So dope was part of life for multi generations of both families. MC parents obviously did and still do have problems, all their kids do, RC and his family, even CS and hers. ugh. Dope everywhere here.
A way of life for them all, would have become a way of life for Haleigh too. I think dope is definitely a big part of what happened that night, but not in a retribution sort of thing from dealers, more so just how strung out all the players were that night is why LE can't get to the truth.
I'm not sure what kind of high they got with all the pills they were doing, but maybe that is why they all fail LDTs because they aren't exactly sure in the fog of their addictions what was reality on that night. Did MC hear certain things then pass out, then sort of wake up and hear cries and thought she was still dreaming so she went back into deep sleep, awoke again briefly, saw another snippet of her surroundings, maybe Joe, seemed like a dream, back into deep sleep, and so on.
Would explain her dreamlike vision of 4 people in the room. Just like you see heroin junkies lose consciousness after they take a hit, they fade in and out of reality but aren't completely asleep, they are still sitting up.
Given how MC was on a binge and exhausted as it was that day, if she did more that evening she would have really been out of it.
That is the part I think dope plays in all this. it has blurred the lines between reality and dream.
The truth lies in the middle.