Usually HDR (high dynamic range) technique is used with static objects as a way of expanding the dynamic range of an image (i.e. you take a series of shots and over and under expose them and then let PS combine then), but it has potential for capturing movement as well. This is made up of five tripod shots of Shea being taken down and simply running it through the HDR process.
Essentially, you can use it to keep the static stuff and just fill in the things that are moving which is what happens in this sequence.
