Depends entirely on your point of view. The Klingon Empire has broken all the treaties it had with the Federation, what's that? And Worf was wearing his sash while he was considered a traitor in TNG (because everybody believed that his father enabled the Romulans access to Khitomer) and during the war with the Klingons in DS9.
That the sashes are KDF rank indicators was Cryptic's idea anyway. In the series they are the crest of a noble house.
Well that rank-indicator thing IMO is another thing that sucks anyway... and its more or less droped with that armor parts we can add now...
They are Klingon warriors. The sash is the mark of a Klingon warrior, and it carries the badges of his or her house, ship, and service be it with the KDF, customs, Imperial Intellegence, Imperial Security (read Police), Planetary or system militia, or House fleets. A Klingon serving in Starfleet is still a Klingon warrior.
DIsacomadation, Being branded a traitor to the empire. These things are of no import other then to blood sucking politicians... and Romulans ::said with a momentous Klingon sneer!::
Blood worms the lot of them. Give them hier sashes. It is thiers by blood right of arms, and the courage of thier hearts!