I was the double agent, Marc Price.
While the Heads were a bit metagamey (ie. shutting down people who were speaking out), the same can be said for some of the revs, who just randomly started gathering in the Chapel and wanting to mutiny, 'cause...reasons.
Anyways, after the RD was attacked, I was reporting the outcome over comms out infront of the Chapel, when the Chaplain (Azazael, a head rev), randomly comes up to me and asks me to join the revs. I immediately declined and reported to the HoS that I had just been asked to join what appeared to be some sort of mutiny or otherwise nefarious movement. I was then asked to join them in order to learn who was a part of the movement/mutiny/whatever it really was. So I went back to the Chapel, and eventually joined.
Fast forward to the Briefing Room situation, and I knew for a fact that Alder (I believe that was his name) and Goodwin were a part of the group, and suspected that a couple other officers were as well (given the statement from Goodwin that "there are more of us in here" when he suggested attacking the HoS). I warned the HoS, and Goodwin has meanwhile gone around whispering the "attack when I say life" to people. The HoS orders him arrested for his suspicious conduct, and as I start to do so, he activates the attack. Myself, the Warden, and Hypatia are the only loyal officers in the room of about 8 people. I stunned Goodwin, and see everybody reach for various weapons (tasers, batons, revolvers), and then hit Alder and Faraj (and possibly someone else). I stunned Faraj because they drew a weapon and had just been talked to by Goodwin right before the attack. I have no idea who released the sleep toxin (it wasn't myself or Hypatia, as Hypatia detained me briefly, thinking I was involved in the attack), and I don't believe it was the HoS, considering that she was preoccupied in the other room.
Just what happened from my perspective, I logged off before some of the later stuff happened due to having to go.