Possible UFO caught on video (cnn.com video)

I don't doubt the video itself (the footage, not the CNN commentary). However, it's quite a hazy circle (wider at one end, almost nonexistent at the other), and it seems to me as though Denna Smith was re-imagining it as something more "perfect" than it actually was.

I saw somebody blow a smoke ring for the first time today, and at first sight it was quite magical. The chances of some smoke from a ride forming a vague ring are much higher than the chances of UFOs (or even super-hi-tech military antigravity planes, one common explanation for these phenomena -- but I think that's unlikely in this case).

Does anyone believes in this?