When exactly did the Markarth Incident take place? Braig talks about his daughter, and mentions that she would have been twenty-three 'this year'. I've seen people say it happened a year after the Great War ended, so obviously those numbers don't add up. Is this just another timeline flub, or did it happen more recently than I've seen people say?
On the other hand, Madanach says that, next to him, Braig has been in Cidna mine the longest. Borkul the Beast has been in for twelve years, which is longer than anyone else names. So more than twelve years. Even ignoring the timeline flub, that means that at most, Braig's daughter was eleven.
This would fit with the accusations that children were executed when Ulfric retook the city. But sheesh. Executing an eleven-year-old pleading for her father's life? This stuff happens in real life depressingly enough, but it's a pretty stark example.
I know people will say that Braig's clearly lying, but the dude's nearly in tears talking about his daughter, and he doesn't attempt to justify anything the Forsworn have done, saying that 'all I've got is my own anger'. He has no idea Madanach is planning to escape shortly, and he really doesn't have any real reason to lie to you (if he was lying for the sake of recruitment, I'd have thought he'd pick a more 'rah forsworn' angle, much like Madanach goes 'remember, it's the Nords who threw you in here'. Further, Braig refuses to talk about it until you tell him that Madanach sent you to ask. This isn't the attitude of a guy lying or exaggerating solely to get Forsworn recruits.