Interestingly worded title - did the car drive itself into the crowd? No, right? Then why would they word it like that?
Anyway, more evidence to support the fact that cars are far too efficient as weapons to be granted as much free rein as they are today. Bollards save lives, implement them liberally throughout any areas with pedestrians.
Or, and hear me out here, the current political climate scares people and those with psychological issues can be pushed over the edge more easily. This man has been known for issues like that according to Zeit online.