On ESMB we toss around the term "Scientologist" a lot, (arguably) using it in the vague sense of "a person who's done stuff in Scientology and uses it somewhat in life." But SCIENTOLOGIST is a trademarked term (currently #183 on my trademarks list at
http://fzglobal.org/trademarks.htm) referring to a member in good standing of the CofS.
SCIENTOLOGY is another trademarked term, needless to say.
Rathbun is committing no crime by auditing people on anything he wishes. He would probably be violating trademark law if he promotes that he is delivering "SCIENTOLOGY services," or is a SCIENTOLOGIST, although the cult hasn't been very active in defending this or other trademarks against freezone or indie auditors. He may be violating CofS copyrights if he, for examples, uses a xeroxed copy of an L1C. If, on the other hand, he uses a copy of Clearbird's statement of the L1C (from, for example
http://www.freezoneearth.org/clearbird/Clearbird2004/sub2/class3/55_1cprint.htm) he isn't as Clearbird's stuff has been online for 10 years or more and the cult hasn't challenged it.
I have about 20 pages full of cult copyright info indexed at
http://fzglobal.org/copyrights.htm. The page at
http://fzglobal.org/copyrights_transfers.htm lists all the copyright transfers I could find at the time (2006-ish), covering at least 30,000 non-unique titles, with almost all of the latest ones being transfers to CST.
Paul