The tail is still there. I went to the youtube link, full windowed the video, paused it and screen shot the part at 5 and 6 seconds showing what appear to be a tail that disappeared. I then cut the plane out and pasted it separately and blew it up 3 times bigger. It has a tail, it's just distorted because the tail is passing through lower and thinner patch of streaming smoke. I also embossed the picture to to make sure, and yes there is a tail. And don't forget, the plane it tilted at an angle with the right wing tilted up and the left wing tilted down causing the view of the tail to be less visible due to line of sight.