Thanks, everyone!
I'd only call it blown for lack of a better word. For lack of a better comparison, it was shaped like a football or goat's pupil, and only a bit larger than I'd expect for the room lighting. It wasn't perfectly centered. None of these were subtle at all. The other pupil was pinpoint and regular, and both were fixed. He was in pretty bad shape overall, so we noted the pupil abnormality but focused on the more concerning symptoms. Given that it was a stroke call, weird pupils weren't really out of place--it was more the type and degree of weirdness that made me wonder about the mechanism.