Should I reference him/her as a normal author or as an editor using the abbreviation 'ed.' (Harvard style)?
Usually, magazine and news articles include the author name at the beginning or the end of the article, or at least some short form like an abbreviation that denotes the relevant author that you could look up. This is the person you ought to refer to as 'author'.
If you're not sure about the author, it would be better denote the editor as the 'editor' not as an author. It would be best to contact the editor to know the identity of the author if possible. But this would not always apply since a few authors prefer anonymity in certain articles.