This is so lame. Look at the image. The image is pixelated. It looks like it was added to the video. If it was really part of the video, it would not show a difference in pixel size.
No, it is not a fire angel.
I heard that this was a guy who was part of a group who intended to rob the store and when they set it on fire, the guy who had gotten fuel over his clothes caught fire, and was running all over before he finally stopped, dropped and rolled. He suffered very bad burns as one would imagine. The story was quite recent - October 2007.