Absolutely, sometimes video seems to be presented as the key to the case, even if it is, as usual, poor quality. I'm thinking of Jennifer, Missy Bevers, and Abby and Libby. I also don't trust the height calculations and they could lead to people being wrongly discounted. Although in Abby and Libby's case the images and voice are reasonably clear and should have helped. But still unsolved...
Whoever is responsible for Jennifer's disappearance took a huge risk in returning her car to a populated area where even if they thought there wouldn't be any cameras, an eyewitness may well have observed it. That makes me think the person on the video is "hired help", who may or not be aware of exactly what he is being involved in. But it seems certain that with all the publicity around the case, he would NOW know so there has to be a reason why he would not come forward.
So he was either very well-paid, perhaps already a criminal, and/or had a personal connection to whoever killed Jennifer. Or he is the killer and just not very bright, was panicking to get rid of the car and got lucky. He didn't take the car very far as if he had he would have had to involve another person to drive him back after dumping it. The only things I see from the video is that he moves like a young, fairly fit person and he has that adolescent male build of being skinny with big feet.
The possible knock on the door late Monday night to me is the key, and I can't believe that as soon as that was told to LE that they wouldn't run that down as far as they could. Statistically, the killer is most likely a man in Jennifer's life or past life who wasn't happy with her decisions. Because of the phones shutting off at night and the knock on the door I believe whatever happened started Monday night not Tuesday morning. But Jennifer appeared to have prepared for work, outfits, had work stuff with her. Possibly she left with someone planned or unplanned and thought she would be able to leave for work from his place, or where he was staying. If it was a random abduction then it had to be in the morning so that her work stuff was with her.
I think her lovelife was more complicated than perhaps has been known, and something that has always niggled a bit with me is that Rob, her boyfriend gives some slightly contradictory information (this is just from memory) in the two tv shows I have seen, one that there was an argument, and also that they hadn't yet got to the point where they had said "I love you", and then another time that they said "I love you" in their last phonecall. It's maybe meaningless but you would think that you would remember what was said, given the circumstances.
I think they need to go back to those males in Jennifer's life and pull apart their alibis for Monday night and do some digging, maybe literally, into the areas they frequented back at the time. But going to be very difficult to get enough evidence after all this time without someone growing a conscience.