In short, the OP had every right to ride in primary, BUT.... he also had plenty of oppertunity to reduce the tension between himself and the aggressive driver should he have wished too. He could have let the driver through, give him a nod and waved him through (it may or may not have helped, I made a mistake on sunday and tried to apologise with a hand gesture, the driver didnt respond how I had hoped, but in general it goes down well). He is not obligated to do so, but one would typically like to avoid conflict where possible and the OP clearly wasnt in much of a rush given his speed so letting the driver through wouldnt have been much of an inconvenience!
I would have just let the van out at that 1st set of lights, it would have been a conscientious decision, knowing that I would be holding him up in the coming section of road.