QUOTE(No one of consequence @ Thu 7th July 2011, 3:40am)
I have no comment as to the accuracy of the guess, but retired arbitrators continued to have full access to the Arbcom mailing list until sometime in 2009 (if I recall correctly). After some controversy over something or other, and some early leaks that may or may not have been Wikileaker, Arbcom closed the Arbcom mailing list to all but current arbitrators only, and also created the functionaries mailing list, which checkusers, oversighters and past arbcom members in addition to current arbcom members are eligible to join.
ArbCom did close off the list to old arbs on January 16, 2009 (but Wikileaker said he had access up to 2/16/09, so I guess that was a typo?). Sam Korn was an ombudsman in 2009--do they have access to the enwiki CU/OS lists?