It’s not hard to believe. It’s not like the neurons connecting the ears to Wernicke’s area magically disappear. The part of the brain which processes one’s name is known to have evolved earlier and is more basely integrated. And there’s no rule that says neurons cannot fire even once after death. Indeed, bodies are known to move or twitch hours after death – so why not there brain, where most of the body’s neurons are?

Arguments for and against: www (dot) cureus (dot) com/articles/133225-the-most-gentle-of-lethal-methods-the-question-of-retained-consciousness-following-decapitation#!/

Decapitation experiments of Louis: www (dot) cairn-int (dot) info/article-E_RHS_612_0333–the-debate-over-severed-heads.htm

“Languille!” he called out the criminal’s name. To his astonishment, the eyes lifted and “…fixed in a precise fashion on mind and the pupils adjusted… I had the impression that living eyes were looking at me”

(this isn’t hours later but it’s the first source I can find rn)

Some organisms have detectable brain activity 96 hours after death (nobody has done this experiment on a human) www (dot) sciencealert (dot) com/how-long-does-a-human-head-actually-remain-conscious-after-being-cut-off

I’m not claiming 100% that consciousness can return even for an instant after death. I just think there’s enough question marks here that it can’t be entirely ruled out.