@golguin: It only happens rarely, but it does happen. (On the PS4 you push R3 when the transparent dialogue window pops up.) The first time I noticed it was at the very beginning of the game. Varric will make a remark about your character's race and origin and you're able to respond.
I haven't seen that before. You are saying that this is something that happens outside a cutscene? You'll just be wandering around in the world, your companions will talk, and the game will prompt you to say something? Is there video of what that is suppose to look like on activation.