Last night my raid team was doing our (best yet!) timed attempt for DP NiM. One of our members made a mistake, which caused us to type /stuck in the hope we could recover the time lost quickly. However despite us wiping, the boss did not reset and continued to cast Endless Torment (enrage mechanic) over and over again.
This occurred on Darth Malgus server, Republic side. My character was Xelthair, and this occurred around 22:32 GMT according to the in-game clock.
Here is a clip showing what happened, as I think this describes the problem best! For context, one of our tanks (Maul Clone) had re-logged to Shadow for this boss, previously having played on a Guardian for the first two bosses.