BG-09 I don't think it is an antenna cable, if it were so to what would it be connected? Also at 6:49 there is a similar fluttering strand that appears to be connected to the front edge of the windshied going on an up angle. I suspect that both strands are hair or something similar caught in shutter mechanism of the camera.
Edit Both strands can seen in this screen shot, (arrows only added).
