Rear lights are so cheap that there isn’t really an excuse not to have one on you.
I always have at least one light fitted to my road bike; normally two and if there is even the slightest inkling that it’s getting dark or visibility is reduced, they go on.
Was the van driver a knob….dunno. Depends on the sort of roads you are riding on, how dark it was, were you dressed like a ninja or did you have any reflective bits….
FWIW, I have rooted at cyclists with no lights on plenty of times but it will either be a toot toot toot from a distance on the approach or a sustained toot, once I am past them – last thing I want is them wobbling under my wheels.
I have also slowed down alongside riders and shouted at them to get some lights on roads where there is space to do so. This normally results in plenty of arm waving and swearing, but hey ho….