Edit: ok, I think I know what happened now. A moderator put 2010 on the title by mistake. I haven't checked the timestamps on the user flags, but it's possible that people flagged the article because they thought it was old, in which case the title change would have acted as a moderation penalty even though obviously we didn't mean it that way. I was wrong to say "moderators never saw it" because I checked the log for moderation penalties, found nothing, and didn't look for title changes. So I made a mistake too.
We're sorry for the mistake. I don't recall this particular thing ever happening before, but plenty of other moderator errors have. We try to admit them and correct them as soon as we know about them.