When we are talking split second reactions to try and save people's lives, the idea of doing nothing is the most heinous of them. Hitting a car that's just tried to run you down and about to do the same to others, not, that's fully justified,as much as punching out a guy with a gun that just took a shot at you.
The driver is done, those photos will be the thing that convicts. He clearly braked as he entered the area with the protesters even as they scattered. He could have stopped, changed his mind, but that second one and the video shows that he didn't. He wasn't scared because someone hit his car, the person that hit his car was one of his victims, one of the people he tried to run over, that strike was self defence and defence of others, fully justified.
That he braked, and then accelerated into the protesters. Nothing will get him off that and anyone defending that sort of action needs to check themselves in the mirror.