She flew back, bounced on the roof once, went over the side of the building bonelessly. Yelped when she hit the pavement in the alley. Yelped like a wounded puppy.
Oran from Broken Saints says this after he attacks his childhood friend Hassan in a cabin fever-induced madness.
This has a tendency to crop up in Survival of the Fittest, usually when a 'hero' character kills somebody. An example of this is Julie Mikan after killing Owen Fontaine, going into a Heroic BSOD simultaneously at the relisation that she has actually ended somebody's life.
Played a bit more straight when the JerkassCorrupt Corporate Executive William F. Drink finally sees the mass chaos for himself and realizes he should have listened to his son all those years ago about the chemical byproduct that trapped the ghosts in their graves and drove them insane.
In Dragon Ball Z Abridged, Dr. Briefs yells "WHAT HAS SCIENCE DONE??" after Goku blasts himself into space on a ship Dr. Briefs built.
King Kai gets one too, after realizing that sending Goku home has resulted in him being all alone again. When Bubbles, Gregory and Bojack try to comfort him, he tells them to shut up.
Bulma gets one when she realizes she hit on her future son.
He looked crushed in Kickassia right after he accidentally shoots Santa Christ.
Said word-for-word in To Boldly Flee after The U.S.S. Exit Strategy and her crew are consumed by the plothole.
She'd never admit it verbally, but The Nostalgia Chick draped her dead BFF's Star Trek shirt over a nearby chair in guilty memorial of the Kirk vs. Picard fight that got her killed.
A villainous - and all the more significant for it - example occurs in A_J of AJCO after she forced Egg into the potentially irradiated and poisonous wasteland above the bunker.
<Facilitator A_J> This is always how it ends. With our betters making an example of us.
<Facilitator A_J> … Why then…
<Facilitator A_J> Am I not content.
<Facilitator A_J> Why then do I feel a grave error has been made.
Aimie_Jane lays down the clipboard, finally
<Facilitator A_J> What has become of me.
Avatar: The Abridged Series- When Sokka rails against the Inventor, saying he's a traitor TO SCIENCE! because he is responsible for all of the "Steampunk Nonsense" in the Avatar world, the Inventor tries to defend his claim, saying that steampunk stuff could work and runs on scientific principles. Sokka cuts him off again, mentioning steam-powered jetskis. This leads to the Inventor having a Heroic BSOD while saying the trope word for word at the "horror" he has perpetrated against the world.
Ayla from the Whateley Universe has a bad case of this when after fighting a demon and being taken away, held and questioned by the anti-mutant police, he discovers that the MCO really do send mutants away to be dissected, studied and killed. Given that Ayla used to be Trevor Goodkind, a member of one of the world's richest and most powerful families, and that in some years he donated more to the MCO than some countries, he was indirectly sponsoring the murder of innocents. While a lot of his friends tell him that it's not his fault and he couldn't have known, the principal tells him that even though sponsoring a legal organisation isn't illegal, by her estimate, the MCO are guilty of 90% of the disappearances, and what happened to the other 10% of the children is probably even worse.
At one point, a supervillain forces Ultra-Man, a member of the Global Guardians PBEM Universe, into making a Sadistic Choice between saving a falling elevator full of school-children, or stopping the detonation of a nuclear weapon (which would have killed the kids in the elevator anyway. He chose stopping the nuclear weapon (and thus saving a city of millions), bawling his eyes out in grief and guilt every inch of the way there.
Worm tells the story of an Anti-Hero who becomes a supervillain in order to do good for her town, which in the process involves some very questionable tactics. It comes to a head in the early chapters of Arc 27 that she finally realizes that everything she did was all for nothing and regrets it all.
Eidolon gets hit by one of these and falls into a fatalHeroic BSOD when Scion indicates that Eidolon may have been responsible for unconsciously creating the Endbringers and thus being indirectly responsible for the millions of people they killed over the last thirty years.
In fact, this is his reaction to the game in general.
AVGN: I feel like I've played every bad game I ever played all at once. And now others are playing it. Because of me! It's like I shared all my horrible experiences! It's all my fault! Fuck this game!*deletes game from his Commodore 64 after realising he can't physically destroy it*
The humans in Void Of The Stars are quite prone to this trope. Especially when they have a religious civil war.
In the WarCraft animation Lords of War dedicated to Durotan during his youth, he is forced to fend off several garn to protect his comatose mother. In the heat of battle, Durotan loses control of his anger, and kills all of the garn, but also accidentally kills his mother's wolf companion, Stormfang. Durotan is visibly distraught and horrified by what he has done. Later in life, he wears the wolf's fur as a reminder of the wolf's courage and loyalty, but also as a reminder that even the most noble of orcs can lose themselves to savagery.
Sketchbook encourages the characters of Don't Hug Me I'm Scared to be creative. It doesn't work out as expected. Somehow they go from doing innocent things like arranging sticks into words to doing very mind screwy, horrific things. The short ends with Sketchbook saying "Now let's all agree to never be creative again" while everyone looks stunned and horrified. Sketchbook is Ambiguously Evil but even that was too much.
In RWBY, this is Pyrrha's reaction to bisecting Penny with her swords by using her Semblance.