So, we apparently have a case of unreliable narrator? Assuming the novel told from the villainess's point of view, then her anger and despair with her father comes down to his spoiling her remotely and never once showing actual affection in person. Gonna go out on a limb and say my "curse" theory is still valid in some shape or form.
Addendum: I'm going to assume that in the original "final scene," Daddy couldn't actually tell his daughter the plan to get her out of there since they'd be watched the whole way (the king did say he didn't trust him), but he so was used to having things go "just as planned" with his student's help that the huge factor he's apparently overlooked for nigh-on two decades (his daughter assuming he hated/didn't care about her) flipped the proverbial table. I'm sure her terror about being subject to torture came from the Crown Prince's reputation and the aggression he showed charging in just sealed the deal. Ya done fucked up, son. Both of you.
Actually, imagining Max realizing his attitude, which his teacher has been warning about for YEARS, caused the critical mission failure amuses me, because he hasn't done much for me to like him at this point.