[kergonath]

> Very large light sources likely helped (as did the matte boxes), but maybe they carefully chose the camera angles as well to minimise this?

All of it, I think. In my experience these ugly flares come mostly from point sources (things like streetlights), so large, soft light sources should help. Also, the matte boxes help controlling where the light that hits the lens comes from, so in effect it makes it easier to have a good angle, on top of making sure that nothing hits the glass at a small angle.