About to do a big multiquote!
Nancy brought up the wrecked car with both AC and TM. Sidney talked about the wrecked car in his interview with Large and TM posted about it on FB. IMO, there is something up with that car.
I believe that TM was using it to follow Heather around town, because it wouldn't have fancy things like a GPS/nav system and it would be unknown to Heather. One of them said the car is now long gone, so I wonder if it was compacted with evidence inside? Or maybe I'm just remembering something far-fetched from a crime show. Ha!
She (her phone pings) spent the most amount of time at LBs. IIRC in SM trial, the phone expert went into detail about her phone moving around while it was there (walking in the parking lot is what I pictured) so she must have gotten out of her car there and why would she get out if she was alone? In my mind, if she were waiting she would have stayed in her car where it was warm. Even if she was smoking (not that I know she was a smoker but DH is so I just throw that in my theories), I think she would have stayed in her warm car. The phone heads back then changes course then goes to PTL (IIRC right?) so IMHO that is the guilty parties figuring out what to do with her car. I think they were going to leave it back at her apt but decided on PTL at the last minute and those frantic calls from PTL were not Heather. Even if they did take her in their truck, I don't think she was the one driving her car which makes more sense b/c how would they get her from her car into the truck without anyone at the apt complex seeing them?
Does anyone have a theory where she did willing drive herself to PTL?
IMHO
IIRC in SM's first trial his lawyer tried to bring out that one of Heather's exes lived nearby Longbeards and could have been there meeting him for her illicit sex escapades or drugs.
Pretty sure there was a sustained objection to it.
I agree with the last of your post, that the later phone calls were not her. Everything after her Instagram/Tumblr/wherever activity I think was Moorers <modsnipped>. I think that's why TM pointed out that SM's DNA would be in her car, so that would be explained away.
Speaking of DNA, didn't they say at this trial that they found cigarette butts but did not test them for DNA? I kinda think they should! Maybe one was that cigar.
ETA - Re Heather willingly driving to PTL. I could see her doing so at gunpoint, but that would only mean she willingly went because she thought she could stall for time or they promised they wouldn't hurt her. So the willingly is more of a "willingly."
Normally I would say that someone who behaves like the Ms have would not leave that sort of evidence but with TM/SM it would not surprise me at all that they had a "flip phone" with a picture of Heather. IMHO TM has at least 1 trophy from that night. I don't know what or where it is but my opinion of her personality from the past 5 years is she would need to keep something close by. Even something as small as Heather's actual key ring or something in plain sight.
IMO
I think she absolutely still has that flip phone and after watching how strongly she hugged PC after her sentencing, I'm betting she stowed it safely on the property so someone she trusts could watch it if she didn't come home. Or maybe it's under the new driveway or under the fire pit. There was some discussion earlier about the trip to see SM's parents, and I could easily see that being a way to dispose of evidence that would degrade due to being outdoors such as that favorite outfit that Bri said was missing or that new unique phone case she had just gotten. So, I'm saying that I think the keys and heather's phone are somewhere on Casa C/M.
Also there were several posts about disposal of her body, and I remembered something. One of the times that TM went on one of her crazy, epic FB-posting rants (OK to talk about the existence of, but not the content in, yes?) was around the time that Horry County officials pulled up a series of submerged oil barrels near a bridge. Prosecutor Jimmy Richards was there according to local news stations. I think if she doesn't know for sure that's how/where it was done (as in previous posts of mine,<modsnipped>), then she had reason to believe it was a possibility and panicked.
Edited to add a few clarifying words and another thought.