Warning: The Following Contains SPOILERS For Titans, Season 2, Episode 9, "Atonement."
Titans season 2, episode 9, "Atonement" explained away what seemed to be a plot-hole involving Dick Grayson's darkest secret, but it did so in a phenomenally stupid fashion. The justification might have been worthwhile had it given the audience any chance of guessing it. Instead, the script either intentionally misled the viewers or was written without any sense of continuity between episodes.
The 7th episode of Titans season 2, "Bruce Wayne," saw Dick Grayson tormented by visions of his mentor, pushing him to tell the truth regarding something in his past. Eventually, Dick spilled his guts to a suicidal Jason Todd, who had come to blame himself for the increasing tensions between the Titans in the face of Deathstroke's toying with them. To stop Jason from jumping off the roof of Titans Tower, Dick revealed his darkest secret; that Dick was responsible for Deathstroke's vendetta against the Titans because he had killed Slade Wilson's son, Jericho.
The precise details of Jericho's death were revealed in Titans season 2, episode 8, "Jericho." Originally Dick had approached Jericho intending to pump him for information regarding his assassin father, who had murdered Aqualad. When it became clear that Jericho knew nothing about his father's secret life as Deathstroke, the Titans were ready to cut ties with him, until Dick learned Jericho had the psychic power to take over other people's bodies. Dick's attempted to recruit Jericho into the Titans; an act which got Deathstroke's attention and led to him attacking Donna Troy.
Deathstroke reached out to Jericho and asked if he could explain himself in private. Dick originally agreed not to follow Jericho to the meeting, but broke his promise after he learned about the attack on Donna. Dick challenged Deathstroke to a fight and lost, only to have his life saved by Jericho, who threw himself in the way of his father's sword before he could deal a killing blow to Dick. The news of Jericho's death broke up the Titans and ended Dick's romantic relationship with Dawn Granger. While Dick was not directly responsible for killing Jericho, it could not be denied that the blood of Deathstroke's son was on his hands.
This seemingly created a plot hole, as the ending of "Bruce Wayne" implied Dick's secret was being responsible for Jericho's death and he was going crazy from the guilt of hiding that fact. Yet the ending of "Jericho" made it clear the rest of the Titans were aware of Jericho's death and blamed Dick for it. The opening scene of "Atonement" attempted to explain this away by having Dick make another confession to the whole team, revealing he had lied to Donna, Hank, and Dawn about the circumstances of how Jericho died. Though there was nothing to indicate this in "Jericho," Dick claimed that he had told the other Titans Jericho was dead before he got to the church where Deathstroke arranged to meet his son and said nothing about Jericho's heroic sacrifice.
While this does explain away the apparent plot-hole, it is hardly a satisfactory excuse. There was no good reason for Dick to have hidden Jericho's sacrifice from the rest of the Titans. He followed Jericho because Deathstroke almost killed Donna, and Deathstroke was the one who actually killed Jericho. Also, if they truly believed Jericho was already dead when Dick showed up, then why did they abandon him in the first place?
While shows like Titans are dependent on a degree of melodrama, this twist went beyond the idea of Dick being an unreliable narrator and moved into outright deceiving the audience by withholding vital plot information. It remains unclear if this was an intentional feint on the part of the writers or if it was the result of sloppy editing and scenes being cut from "Bruce Wayne" and "Jericho."