When you put that much power on slicks (with probably in the area of 5 PSI) the car, when even slightly out of shape, will "roll" the body over the tires, making it swing back and forth. If you're lucky, it straightens out, if not, it puts you sideways, then the slicks grab, and away you go. It does appear after the initial rolls that the throttle hung a bit, just making things worse. Watch it in slo-mo and you'll see just how much the car moves around on the tires.