Okay okay NS. I've really analyzed the video a billion times and finally came to a conclusion.
Flat 270 cork 270. The first flip is thrown like a flat 360, but when Dean comes upright after the first inversion, his skis are perpendicular to the landing rather than parallel, only doing 270 degrees of rotation. From there, it's similar to how someone would throw a switch cork 3 off a jump, but since he started the second flip from a perpendicular position (90 degrees already completed) it only gets 270 degrees of rotation.
Here is another way I kind of look at it- Remember vinny gagnier's switch rodeo 5 air pretzel 1 that blew everyone's mind, where it looked like he was was taking it to 5 but it only ended up being a 3? Well this is a dub 7 air pretzel 1 (extremely stupid name), where it looks like he is taking it to a dub 7 but only ends up at 5.
When I first watched the clip I could have sworn it was just some wonky dub 9, but if you were to stick dean's head on a vertical axis during the trick, it only does 540 degrees of rotation. I'm certain.
It is a double inversion and it's only spun to 540 on the vertical axis. Beyond that, what the trick is called specifically seems somewhat moot.