Eddington's switching sides wasn't particularly horrific either. He had no vendetta against Sisko and did what he did to support a cause he thought was right. The guy stole some replicators, which i'm sure the Federation would have easily replaced. Whilst Eddington also betrayed his oath and uniform That was never Sisko's motivation for going after him.
I know that no one died but whether people were killed is irrelevant to the point i'm trying to make. Sisko turned into a raving lunatic who poisoned a planet putting innocent lives at risk and initially displacing hundreds possibly thousands of people. He did this not because Eddington was a Maquis, but because Eddington bruised his ego and made him look like a fool.