Couldn't you just leave? Like what if you had genuinely been there intentionally but had an emergency at home? People understand

Doug Englebart and Ted Nelson came to give a lecture at my university when I was a student. I was busy in the lab and engrossed in my work, and realised the time 5 minutes after the talk was due to begin. I was too embarrassed to walk in late, so to my eternal regret I didn't go. I'm more comfortable with that sort of situation now, but I can appreciate the desire not to make a scene.

Yes of course but most don’t think that