“Rosenberg, who says he is a science fiction writer...”
Stupid author of this article. Joel Rosenberg *is* a science fiction & fantasy author:
http://en.wikipedia.org/wiki/Joel_Rosenberg_%28science_fiction_author%29
Yes. The construct of that sentence is a typical sign of a lazy journalist, who is too stupid to research, or too scared to mess up his research and get something wrong.
By saying “says he is”, the journalist is certain that he got the facts right, since the journalist has a recording of the person saying that.
This happens all the time in election coverage. Rather than research, reporters just quote the two campaigns, even when they are disagreeing about something like whether a candidate voted for or against a bill, something easily learned by looking up the records.