Title says it all. I had a situation where a moderator answered a question and then marked another answer (that said the same thing, but more directly) for conversion to comment because they felt "its length was not up to community standards".

While I think it is important to maintain some set of standards for answers, I don't think it is appropriate for a moderator to remove (and therefore penalize) other answers to a question in which the moderator has also provided a "competing" answer.