I waited until I read the whole thread and since I didn't see an answer, I'll give you mine.
As I mentioned earlier, I have been to about four houses in Great Waters and ten or so in the original Reynolds Plantation development. Now I have not been to the Dermond's house, but every single place I have been to has had detached garages.
They are usually 3 car or larger and are set at an angle on the driveway catty-corner to the main house. (Remember, this is a lake front property and no one wants a garage visible from the lake)
Since the garage is detached, there is a normal type door on the side which runs on a [usually covered] sidewalk to the mud room entrance. Guests come through the front door.
Most of these garages are large enough that the guy can set up his hobby next to his cars. Most had woodworking stuff. Meaning..."decapitating" tools could very well be right there in the garage. No need to necessarily bring them with you.
My guess is that the poor man was taken in, or just in front, of his garage and the slight movement was to hide him behind the parked cars. Since there is (more than likely) a side door, no reason to have to run under a lowering garage door to get back out.
To touch on a few things I read on the thread along the way:
This is a long, relatively thin, finger shaped peninsula sticking quite a ways into the lake. The subdivision takes up ALL of the land. The only vehicle-capable way onto the peninsula is pass the guard station. No way there are campers anywhere near there.
No way there are drifters.
No way there are gangs.
No way there are meth heads.
As unreal as it may seem, these scenarios are the least likely to have happened in this puzzling case.
