She'd been there for days, so the dog(s) could easily be confused by her travels around the property. Her scent was everywhere, I'd imagine. Cadaver dogs still have limits, and I'll have to refresh, but recent death via cold exposure is likely to be the toughest to get a hit.
As quick as the area was crayon-drawn as checked, I'd lay odds that the search was inadequate.
Broken twigs is made for TV stuff. The area is sandy, marshy, densely wooded with Pines that deer, coyote, and even the occasional bear barrel through, and I think there's a swath that was wiped out by tornado a couple years ago, north of the green cabin. Tracking via footprints and other physical means is highly improbable. My family's property is on the other side of that marsh. It's not easy travelling on a good day. Barefoot, panicked, at night, slim to none. She'd know that, if not in an ASOC.
I don't recall seeing any solid sign of a second gun. The glass almost all goes out when shot, and the large hole could have been a fluke, double-tap, anything. Angle from hitting her car, window holes, her height, GSR, should point to where she stood.
Boots off, on the roof, at night, is great for watching the stars, listening to nature, or maybe enjoying your favorite recreational that may have an odor not appreciated inside a shared vacation spot.
Without identification and details of the friend called, I'm still very suspicious of that side of the possibles. I'd think they'd be interviewed and on the news if they had firsthand input. IMO, if there was foul play, they're part of it. If AQ was in an ASOC, and the friend was called to talk her down, and/or because 911 would have brought attention to possible cause of the panicked state.