This episode portrays Williams in his, in my personal opinion, finest. I can say I never 'got' Williams' unique and offbeat comedy. But after seeing him in One Hour Photo, I developed (no pun intended)a new appreciation for him.
Here he portrays an evil, intelligent almost genius mindset, manipulating people into doing things, then blaming them for having a herd mentality. Especially nice was his taunting the doctor who he blames for the death of his wife and child. He continues to call the doctor, pretending to be a police officer telling him over and over that he knows what the doctor did, till the doctor finally can't take anymore and commits suicide.
And the end was great. Though I had a hunch the screams were pre-recorded from the start, it still played out well. And I like the idea that it's left open. Maybe we'll see Williams again.