I had to redo "Tinker, Taylor, Soldier, Die" twice because I thought the mission had a bug since half way through the mission you are presented with a just single option "This is above my pay grade." which quits (fails) the mission.
This particular instance should at the very least have another option "look for Brigette", but I really see no point in the "This is above my pay grade." option at all. We can always quit the mission if we just want to abort and the first time through the mission I honestly thought that this was a valid story-line and my character was just asking for more money - why would I even be playing the missions if I just wanted to quit early?
The Wikidot walkthrough shows 5 different places like this where you can quit (fail) the mission early. The walkthrough never even makes it through the whole mission so there might be more. I have no problem with real failures (e.g., "Never give up" option in that mission when first checking out the mausoleum), but pointless quit options don't make sense. Many of the missions seem suffer from this issue.
I admit that usually it is obvious which options are pointless quits, but their presence is jarring and the fact that they are so common makes me occasionally afraid to choose some options for fear that they might be just pointless quits.
Anyway, now that I'm done ranting :) this post is a vote for a significantly reduced number of quit early (fail) options in missions. Thanks!