They put him in a position of danger that he was then forced to avoid. Sure, I doubt they set out to have a crash so the intents different, but the fact remains that they put him in the position of it being possible by ignoring the rules of the road. Now, you may not get angry at that, but I certainly would and it would certainly be justified.
Getting angry really helps no one, though.
It's one of the things that amazed me about driving in India, everyone is cutting everyone else up etc but no one gets angry. It's weirdly more chilled than UK driving.