One would think that making a mistake at a roundabout would be less costly than in T junction, yet it was not so for the driver of this white van.
We're not exactly sure why he did what he did, but he must have been going really fast and either paying very little attention to the road, or perhaps experiencing some issues with his brakes.
Either way, it seems everybody involved was unlucky. There could have easily not been a vehicle on the other side of that roundabout to crash into, at that exact moment in time.
As somebody in the comments section points out, the driver could have also been from a left-side drive country, which is why he went left when he realized there was no way of stopping in time.
Of course, we can only speculate on why this incident really occurred. What we can be certain of is that if the van was going slower to begin with, the driver would have had more time to mitigate the impending crisis.