Reviewing this just makes me want to murder him all over again. (Or rather, murder for the first time. You know, because I haven't been allowed to yet.) You need to bend over backwards to get these scraps of affection before he shoots you in the face anyway.
I hope they bring the option to kill companions back when they expand on the class stories... I'd also expect some kind of resolution to this whole situation, even if it was a 'lengthy' process, not just "I forgive you, lets get going"
That's later in a different conversation, when you find Rathari's message on Halidrell's corpse.
Rather than a long explanation I just uploaded 2 of my vids:
If you spared the Republic troopers you get this version (with my juggernaut).
I think it's different than what you did because I asked Quinn to thwart Rathari's ambush himself.
I found that asking his opinion, or pretend that you are clueless and need to rely on his expertise often brings out the best conversations.
I miss out on so much when playing with my brother, he's not quite as into the cut scenes and dialogue as me, so I just go for the +affection.
I remember selecting that option thinking that it might give +affection since you're acknowledging his skills and abilities, hehe, maybe he doesn't like to work as much as he implies.
On a side note... I find Quinn funny, sometimes he states the obvious, and other times his responses are just so far... detached... I can't help but laugh...