If I'm not mistaken, Wally accidentally kills a guy, and then actually frames someone else for it, rather then take responsibility, leading to the other heroes on a mild goose chase through several issues. I believe hat one point hen tries to travels back in time to kill himself either to prevent it from happening or to keep him from ratting on himself
However, it's treated as a mental health story, and by the time it's over the other heroes just forgive and forget and Wally faces no repercussions for his actions
Someone please correct me if I'm wrong. I stopped reading DC comics a long time ago