In episode 4 of The Walking Dead: Dead City, titled "Everybody Wins a Prize," a flashback explains one of Negan's odd decisions as the leader of The Saviors. The spinoff series explores the redemption of Negan, who is forced to team up with Maggie, the wife of the man he killed, to rescue their kidnapped son in Manhattan. The episode opens with a surprise cameo from Negan's former henchman, Simon, who reveals why Negan turned against another Savior leader, The Croat. In the flashback, Simon tells Negan that The Croat tortured and killed a young girl, despite being ordered to let her go.
Although the girl was later revealed to be a scout for The Kingdom, Negan is disgusted by The Croat's brutal act. Simon, who claims that The Saviors draw a line at hurting children, becomes Negan's right-hand man after Negan fails to kill The Croat. However, history proves that Simon is impulsive, overambitious, and disloyal, ultimately hindering Negan's leadership. Negan eventually kills Simon after he tries to take over The Saviors. This flashback sheds light on Negan's decision to trust Simon.
Despite his brutal persona, Negan had moral lines he wouldn't cross. The death of the young girl made Negan lose all trust in The Croat, and he believed Simon would be easier to control and remain loyal. However, in hindsight, Negan regrets this decision, as The Saviors may have won the war against other communities with The Croat by his side. This flashback scene also highlights an issue with Dead City's portrayal of Negan.
Negan doesn't act like himself, allowing Simon to do the talking and expressing moral outrage. It contradicts the portrayal of Negan in the main series, where he owns up to his actions as a monster and works hard to earn trust from other survivors. Dead City attempts to rewrite Negan's past, depicting him as a remorseful leader trying to do his best in a post-apocalyptic world. However, this isn't consistent with who Negan truly was. Overall, the flashback in The Walking Dead: Dead City explains Negan's decision to trust Simon and showcases the show's attempt to reshape Negan's character.