All I can say is “wow”. There is no swing like this on Tour, and I don’t think I’ve ever seen anything like it ever. Dustin externally rotates his right arm to the max right from the beginning of the swing and keeps it that way through the backswing, where he takes it past parallel with the driver, all the way past impact, and while he’s at it he forward flexes his left wrist from the get go and also keeps it that way past the ball in the ultimate example of a “drive/hold” release.