this was 'good times!' but I'm confused about one thing. (spoilers)

This movie was a riot but I need help with a scene. I watched this when i was tipsy, so I could have easily missed something.

When they are driving to the punk show, the wife is telling Side-Pony girl about all the crazies that her husband works with. At one point she says, "you know that guy from a few years ago who strangled people and would get nose bleeds?" and Side-Pony says "THE BLEEDER is with you?!"

So...I'm confused. Side-Pony and Mrs Potter go to a nuclear power protest. They get arrested and some guy who also got arrested at the protest and popped by the police lets Mrs Potter cut in line to use the phone. He gives them a lift home and they invite him to stay for dinner.

Towards the end of the antics, the guy is hugging Side-Pony and starts bleeding all over her face. She looks up, he chokes her and tries to kiss her. Mrs Potter says "THE BLEEDER!"

Ok.

So, Mr. Potter was there during the whole little dinner and directing the dude what to do when the mayhem ensued. How did he not notice he was one of the patients at the institution? Maybe he has never met this patient and just knew he was with him? But why would THE BLEEDER be protesting nuclear power? That isn't the first thing I'd do if I escaped from an institution. Is this indeed THE BLEEDER or is it another person with the same, uh, psychotic problem?

if this is just a simple lapse of logic, ok. but any help would be appreciated!

My mother always said, "Feelings are like treasures, so bury them."