I hope he wasn't on the phone before he crashed.
Looks simply like a mix of rain/wet roads and too much acceleration.
Something very similar happened to me years ago in my M3 - I was driving in town along a straight dual carriageway (30-40mph) and came to a very slight righthand bend. There was light rain but grip had been good up to that point. The road ahead was clear, when gentlly accelerating the back suddenly stepped out and swung 180 degress before the grip came back and the car righted itself. That was a brown trouser moment for both me, my gf and the chap in the lane next to me who was looking at my headlights at one point.