Theory Update
Well, I just had another look at the NTSB B-Roll on the crash site, and from 2:54 - 3:00 of the video, fairly light tire/skid marks are shown leading from the movement area to the crash site. I may have to adjust my theory on this crash or just consign the whole thing to the "Dust Bin Of Flawed Theories" (DBOFT).
Time (and further NTSB investigation) will tell.
Regards,
Grog