Sure, he has the right of way indeed. However that doesn't mean he's not an idiot.
1 ) He approaches a side street with lots of cars going in and out of it, some of them blocking the others' vision. Any sane person would slow down to a reasonable speed and get ready to brake hard, right of way or not.
Having the right of way doesn't mean you can just plow into any dangerous situation at such a speed that you can't stop anymore. Especially cyclists and motorcyclists should at all times ride defensively because they don't have a crumple zone.
Cycling on public roads, rule #1 : Always assume you're invisible and everyone else is mental.
2 ) The Golf driver didn't pay attention indeed. He had a clear view of the road at least half a second before he initiated his turn. It's a common mistake, but a mistake nonetheless.
HOWEVER : The cyclist had plenty of time to anticipate this. I saw it happen even before he started to turn, simply because he didn't stop. The cyclist even mentions seeing both cars and the ones before them (7:50-ish), so he was aware of the situation.
Not only did he fail to slow down as he entered an obviously dangerous situation, once it happened he didn't do a damn thing about it either. I don't see him slow down at all. He didn't move to the left either, which would have been another way to avoid the crash even without braking. He didn't even shout, which will usually attract car drivers' attention when they're doing a maneuver and cause them to hit the brake for an emergency stop. You'd be surprised how hard you can yell "Oi !" in a dangerous situation.
It's almost as if he approached the street and thought "oh sod it, If he turns, I'll just hit him, fall off and have a nice payday". Probably didn't count on the Focus running him over.
Actually, the first thing he says is that he wants the guy's insurance number, even before he checks himself or his bike out. Smells fishy ...
As for the lights, at around 5:30 you can clearly see the front light for several seconds. I wouldn't notice such a weak flash if I were driving and looking out for other cars.