The Walking Dead Season 8 Implications: What 'Mercy' Really Means
6. Dwight Can Be Trusted (For Now), Eugene Is Firmly Negan
Dwight isn't in the episode a lot, but he does play a key role in coordinating the attack on the Sanctuary. Having switched sides late in Season 7, it confirms that Dwight is very much Rick's inside man among the Saviours, working against their common enemy Negan.
It means Dwight can be trusted, but it does feel like there's a 'for now' caveat to that. Dwight is doing what he is because of his hatred of Negan, but Austin Amelio has also described him as a "lone wolf" this season, and said that the angel on his shoulder is talking louder than the devil right now.
That indicates he's not fully on Team Rick, and there's a good chance we'll have a few occasions this year where Dwight's loyalties are called into question, while he won't be forming part of the team if/when Negan is taken care of.
Going the other way, having previously been on Rick's team, is Eugene. There were doubts about where the character's loyalties were after he helped Sasha commit suicide (and almost take out Negan) in the Season 7 finale, but this episode makes it clear: Eugene is Negan, and even if he did want redemption that road may now be closed off.