LE is not going reveal any details to anyone that is not on their team. Just to prove this, I had a friend call as well. They told him that they have not discounted any theory. He is a federal officer but not in the area and not involved in this case. They are aware of this speculation and would not comment specifically either way. They definitely did not say that her bike is not under the truck.
He has a good 13 years working in federal investigations and also can see that something is going on in this pic. And, feels that it may be the only pic that shows such detail of the truck. He also said that it may not be a video camera that is pointed in one direction...that it moves from side to side and only caught glimpses of that view. Makes sense to me. After all, why would it only be pointed at that one spot? The timing makes sense.
And, for those that are completely closed to the idea...how do you explain what is seen? For those that keep discounting this theory because they cannot make out the photo's... Try. And, the light under the truck is not on the other photo's. There is a reflector light in the other lane but that is the only photo that shows a light in that spot.
Personally, I think PI's are an invaluable resource to any investigation. Less based and more time to focus, no red tape. Many years ago one practically saved my life by tracking a stalker that was threatening me. Unfortunately too many policeman don't feel the same and may or may not provide them with accurate info. Guess they feel like they don't want to be shown up!