Good find.
Positioning in the video looks "close to" neutral. Not close to either stop. Unless it jammed there (and neutral was not the trim needed) or the whole unit broke loose from its mounts, that seems to minimize the odds of a THS jackscrew problem. (But you just never know).
On another note - probably having no significance to the accident - I have tentatively ID'd the "biggest part found so far" (shown at 5:10 in the reporter's first walk-around video, post 362) as the bottom half of the left winglet, and its junction with the wing tip.