I may have found a bug (in case this wasn't patched out yet).
This was during the debate. I chose to go for the Prime-time TV debate, and I guess that depending on the options you pick and your own stats, you get different outcomes. I managed to get the flawless outcome + achievement.
Occasionally, I'd check out my stats every now and then. It was during this time that I chose to do so. And after toggling it off, I thought my eyes were playing tricks on me, but my debate results changed. This does not seem to happen if you click the "Next" button to switch off your stats. But only, if you use the "Show stats" button to toggle on or off. This is for the PC version, I should add.
Now, I suppose this is a nice exploit. Because I netted a good result on another round, but after toggling the button a few times, I got the flawless result.
Also, I don't know if this was supposed to happen, but after joining the F3, Jonas would sort of "make a move" on you. I chose to avoid the kiss but stayed peaceful. However, he still came after me (and got killed), then everything happened as if I never heard of the F3, and I got a normal ending. However, this might be the way it's supposed to happen, so just asking about it.