Take primary through pinch-points where possible. I think the driver should be prosecuted - cyclists have been killed by drivers like this, in this situation. It's not hard: stay back; wait until the cyclist has cleared the pinch-point and only over-take if it is both safe and practical.
the cyclists were in a group right? in a single line? or two, three abreast? does this explain how its easier to pass a group of cyclists side by side, rather than strung out, putting the overtaking vehicle at more risk of a collision with oncoming traffic due to being sat out for more time?
Take primary through pinch-points where possible. I think the driver should be prosecuted - cyclists have been killed by drivers like this, in this situation. It's not hard: stay back; wait until the cyclist has cleared the pinch-point and only over-take if it is both safe and practical.