A common example not cited in the description is when Bob murdered Alice and blames/gives a "that's on you" speech.
Sometimes will go as far as to say it's not his fault in anyway but only Alice's for not stopping him.
Sorcerer in training
"A random woman once berated Superman for being off-world during the "New Krypton" storyline — while trying to stop a war — while her husband was having an aneurysm."
I found this particularly stupid because she's focused on Superman, when there are several other heroes whose powers could have done the job (even excluding magic). If they'd got there in time; in a med class I took, I learned an aneurysm can kill in less then five minutes, maybe ten.
Coming back to where you started is not the same as never leaving. -Terry Pratchett
The title is a bit of a mouthful, and confusing as to what it really pertains to. Perhaps we can change it to "Could have saved them" since that is what the character(s) usually say to The Hero.
Murder by Inaction used to be covered by this trope. I moved all the examples I could find from here to there, but if you see any I missed, please move them. Thank you.
"Get me a gun, I'm a soldier; but put me in that suit and I'm a superhero." - Gunnery Sgt Roberta "Bobbie" Draper MMC