I've watched it ten times. He raises his arm as the van passes too close / turns in - and yes, his raised arm would offer no protection at all, but that's why I typed 'instinctively'. The driver is a complete moron, anyone attempting to justify his actions not far behind.
So derrrrrrrrrrrrrrrrrrrr are you calling me a moron.
Clearly not, unless you were driving the van? If you think there is ANY legitimate justification for his actions, you can put yourself in the 'not far behind' category, though.