What he should do is file a DMCA counter-notification, which would require Zazzle to restore the product unless the Tolkien estate files suit within 10 days:
The following shall not be actionable as dilution by blurring or dilution by tarnishment under this subsection:
(A) Any fair use, including a nominative or descriptive fair use, or facilitation of such fair use, of a famous mark by another person other than as a designation of source for the person’s own goods or services, including use in connection with—
(i) advertising or promotion that permits consumers to compare goods or services; or
(ii) identifying and parodying, criticizing, or commenting upon the famous mark owner or the goods or services of the famous mark owner.
http://www.cs.cmu.edu/~dst/Terrorism/form-letter.html