According to the patch notes:
"If you want to start over from the beginning, simply abandon the quest and pick it up again."
This does not work. I abandoned the quest, but no matter what I do, I do not get the option to pick it up again. I logged out, exited the arena, started a normal maelstrom run, shut down the client completely, et al. Every time I re-enter the area, the questgiver just stands there and the portal always goes to the arena where I left off/abandoned quest.
Make Rush of Agony "Monsters only." People should not be consecutively crowd controlled in a PvP setting. Period.