While shopping for houses, Louie looks out the window of one and sees a crazy hobo muttering to himself on the street. A black car pulls up and two dark-suited men jump out, who stuff the hobo into their car and replace him with a nearly identical, also crazy hobo.
On the way to his aunt's house in Pennsylvania, Louie stops to fill up. As he does so, two Sikh children in suits stare at him in silence.
When Louie is knocking on his date's door in the first episode, the old next door neighbor chides him for making noise as she is naked in her apartment. Eventually, she opens her door fully so the unimpressed Louie can see her standing naked. She calls him a pig multiple times and then slams the door.
At the end of his date in the first episode, the girl jumps off the bench where they're sitting and runs out to climb into a waiting helicopter, which takes off.
Louie and Maria Bamford watch a Big Brother-like show in bed. At one point, one of the contestants psychotically snaps and stabs another in the heart with a knife. Louie and Maria don't react at all.
In the fourth season premiere, Louie is awoken to the sound of garbagemen making a racket outside his apartment. They get progressively louder as they bang cans together and shout at each other, eventually breaking Louie's windows, crawling into his apartment, and trashing his bedroom while Louie is still in bed. Louie treats all this as a routine annoyance and goes on with his day.
"Elevator Part 4 and 5" both start with a news broadcast about Hurricane Jasmine Forsythe, which destroyed Cuba and Florida. The newscasters talk about it so casually that the whole thing sounds like something from The Onion. None of this is mentioned afterwards (in that episode).
In "Elevator Part 6", the hurricane reaches New York. The news announcers again talk about it casually, saying things like "Now, as you can see in this map, everybody in this part of Western Brooklyn is already dead. Everybody in this part of Brooklyn will be dead by 4:00 tomorrow.". Lower Manhattan is flooded, and Louie has to rescue his ex-wife and daughters. Again, none of this is mentioned afterwards.
In "Elevator Part 4" again, when Louie and Janet visit a therapist about Jane's behavior and while the latter two are deep in conversation, Louie, frustrated that he isn't making much headway into the conversation, gets up out of his seat, walks over to the window, opens it, sticks his head out, and screams as loud as he can into the streets of Manhattan. After he is done venting his frustration, he pulls his head back in, closes the window, walks back to his chair and sits, where Janet and the therapist are still deep in conversation as if nothing out of the ordinary had happened.
In the cold open of "Cop Story," while Louie is shopping at a cooking ware store and had a mild argument with the owner, he turns around and makes out with a bust.
Funny Background Event: While not necessarily an event, in one scene of Todd Barry and Louie talking in a coffee shop, literally everybody in the background is standing still and staring down at their phones.
The southern policeman.
The lifeguard in Florida, so much that his ex-wife and even the guy mistakes the friendship for romantic interest.
There's an episode where Louie is picked up by Chris Rock after going home with a woman turns out bad. While at Chris' house, Chris' wife is rude as hell and it's made clear he tolerates her more than loves her. His actual divorce in real life after this came out can make this scene a little harder to watch.
The show features several scenes, both real and imagined and both serious and comical, of characters being forced into sexual situations against their will. These play very differently after the New York Times story about Louis C.K.'s own sexual misconduct. For example, in one scene Louie tries to rape his friend Pamela. In another, Louie tells Ellen Farber, an anti-masturbation advocate, on live television that he's going to masturbate thinking of her. There's also this exchange:
Farber: That's what's so sad. That you don't know the darkness that you live in. Louie: Oh no, I know the darkness.
Jerkass Woobie: Lenny (played by Michael Rapaport) in "Cop Story". He's a police patrolman who uses what little power he has to bully Louie into spending more time with him, and then aggressively belittles him the whole time that they're hanging out together. It's understood that he has a history of boorish behavior, and things get so bad that Louie actually blows back at him. However, it soon becomes apparent that Lenny is both aware of his alienating faults and is plagued by self-loathing as a result. It's also implied that this is why he's never risen beyond the duty of patrolman in the last 19 years. Eventually, when it's discovered that he misplaced his gun at some point during the episode, Lenny breaks down, decrying himself as a failure. It's what drives Louie back into empathizing with his former friend, to the point of finding his gun and returning it.
Moral Event Horizon: Louie tries to rape Pam, then forces a kiss on her. Pam calls him out on it, saying "You can't even rape well!", and it's mostly played for how pathetic Louie is, but it definitely seems to be the lowest the character's gone so far.
The Woobie: Louie. Some episodes don't hold back in showing what a tortured, psychological wreck he is.