I was once cussing at a stop and go driver, only for the driver to get out and point at her throat. She was choking on her toast. We got it cleared and she was okay.

Assholes seem to be more common than medical emergencies though.

50% chance it’s just an asshole

50% chance they didn’t see you were putting air and wanted your car out of the way, thinking you were the asshole.

Maybe he just was honking to alert you of his presence to avoid an accident?

He just saw someone with a mask and a bloody axe creep into the back seat of your car.

My Favorite human phenomena is that most drivers will use the horn when their safety could have been secured by applying the brakes