The thing is, Quagsires was clearly one of if not our best villager at that point. He was posting a lot, and his posts were almost all very informative and well thought out. A one-for-one between the mafia and village like that inevitably benefits the mafia. Yes, OD had to sacrifice himself to do it, but this late in the game it'll be harder and harder for him to avoid targeting his teammates anyway. We have no more inspection roles, and from what people are saying, potentially no more vig. Now would be a perfect time to do that. The question is, why would OD sacrifice himself and now have one of the less trusted mafia post that? Simple. If it had been anyone else, we wouldn't have trusted it nearly as readily. It's quite likely that we wouldn't have believed the mafia, and it would have forced OD to buddy with that person, potentially giving us two mafia for one. With OD doing it, we trusted him almost readily; after all, he was one of the most trusted villagers, leading us to off one of our most helpful villagers.
As for the role that OD claims, I'm not buying it. First of all, question asker is usually restricted by not being able to ask about Smogon names, roles, and alliances. To be fair, this one is also restricted, but in a different way (one-time and insane), but it's still noteworthy that he's claiming a version of question asker that is rarely seen on Smogon. Speaking of insanity, there is almost always some sort of hint to insanity in an insane inspector's role PM. If there was, then OD should have picked up on it, and if he were village, he should have mentioned that there was a chance his role was insane. Instead he doesn't mention it at all. Finally, a role that can ask a question at any time and get an instant answer is even more odd. If there was a question asker in the game, he would ask his questions at night like every other role. And that is literally the only way to explain his actions; why else would he try to argue us into a Quagsires lynch first, then only after realizing we weren't biting reveal he was a question asker? Either because he's actually telling the truth, which is highly unlikely in my opinion, or because he was mafia trying to get our best villager lynched and didn't have enough sway with the village.
All in all, Lynch Orcinus Duo seems to be the thing to do right now. There are 10 of us left and at least 2 more mafia, possibly 3. We have the room to make at least 1 mislynch if OD happens to be telling the truth, and if he is at this point he's a vanillager and thus role-wise as useless as anyone else could be. While yes, he would also be the best villager left play-wise, we cannot trust him after this, which makes his opinions difficult to believe. Once he's dead, we can build our opinions off of his depending on how he flips.