The Reason why he lost it was because he braked while in the slipstream of JB's car and then realised he was going to go into the back of him so pulled out however that meant the left hand side had more grip because of higher downforce and started the car skidding.
Yet its still really stupid and if he turned right to stop the oversteer where did he think he was going to go

vettel will never win a world championship until he calms down a bit.
hamilton was a bit like this in his first year on and off the track yet he has matured much faster than vettel and vettels been in the sport longer i think