Is peer review confidentiality overridden when the author is suspected of misconduct?

The following case study was published by the COPE (Committee on Publication Ethics): Editor A wrote to editor B, indicating that one of the reviewers of a paper submitted to Journal A contained material that had been submitted at about the same time to Journal B. Editor A requested a copy of the paper submitted to Journal B. Editor B responded, confirming that the paper in question had been submitted to Journal B (submission date two weeks earlier than the paper submitted to Journal A),