My main character is on the side of the angels, but he gets a bit too hardcore in pursuing justice. His motto, he at one point says, is "Let justice be done, fuck all the rest." He's willing to do anything to see that good triumphs over evil. Outside of the struggle, he's a bit of a Jerkass, but not an unlikeable one.
So at one point there's a guy, a high-ranking Naval officer, who is not really a villain, who could do the right thing at some little cost for himself. He's also a closeted homosexual, in a balanced relationship with another officer, something the main character uses to blackmail him into doing the right thing.
So is the blackmail in this instance a case of kick the dog, or does it veer closer to the moral event horizon?