Bioware seem addicted to cancelling stealth in all of their games, completely throwing away one of the key aspects of the roguish class. Any cutscene? Cancel stealth. Any conversation? Cancel stealth.
One of the most annoying examples is when your stealth gets cancelled by the boss of the other side giving some “I will destroy you!” speech. Well yes you probably will now that I’m just a poor man’s fighter.
The optimum plot-following character in Bioware would appear to be a kind of Charisma tank, good enough to pass the Skill checks but armoured enough to handle the aggro of a conversation tree that is going to always end with the other side attacking the speaker.