Is this a bug? Or is it a feature by intent of StackExchange engine, specifically, to allow a user to answer the same question twice?
A question on Writers.StackExchange (beta): Referencing a website using Harvard style
Same user, slightly different dates. First was on 1 Mar 2011, second on 22 Mar 2011. Both are good answers, in fact, different parts of a total response. I suggested an edit that would merge them, has not yet been reviewed by moderator.