Assuming you could occupy the right seat as a passenger under 135.113 you would be considered a passenger. There is an existing interpretation under part 91 that a person receiving flight training is considered a crew member (this stemmed from an interpretation where flight instructors are exempt from the passenger carrying recency rules while engaged in flight training operations).
135.115 further complicates your issue and is open to FAA interpretation.
Although I can't find any references for it (may be an ops spec issue) I believe flight training may not be given during a 135 revenue flight.
Besides, the claims that you were only receiving training in radio communications probably won't pass the FAA smell test.