If PS3 didn't suck so hard it probably wouldn't be coming out for the PS2
Jetii have been battling Mando'ade for centuries. It stands to reason that at least one of the di'kuts would learn the advantages of beskar'gam, especially during the outset of the Jedi Purge. Also he could have made nice with some mandos and got a gift, it worked for Bard'ika and Etain.
possible, have you read flash point Vasili? i remember mando'ade doing testing on jeedi, maybe one of those finally found force powers but went dar'manda. rat bastard kept his armor but left his clan.