I believe it's a reflective artifact of sunlight. I'm not an image analysis expert, but look at this:
http://uncinus.wordpress.com/2010/11/09/4/
Alright. Your sources have me convinced. Without having been able to see it and judge it with my own eyes, I’m willing to believe it’s very probably a jet contrail.
I think there’s a quality about the video that leaves some doubt, mainly the density of the plume that we see and its seeming proximity to the ground. But I’m no longer so certain as I was.