Nightmares & Dreamscapes: From the Stories of Stephen King (2006)

S3E13 Cornered

Johnny finds himself in a precarious situation when he inadvertently kills a feared gunman due to a misfire from the killer's own weapon. While the townsfolk celebrate him as a hero, Johnny grapples with the reality of what really happened. Soon, he discovers that the gunman's son is on his way, seeking revenge for his father's demise, and he has a reputation for being even quicker than his father was.