I think it's kinda funny how his ability is "brainwashing," and yet he doesn't even use it when picking up girls and instead uses it on himself to get a confidence boost.
Also, despite what everyone's saying, we don't know that she didn't go into her lecture anyways after the "you're wrong." Because at the point she saw that, she must have already prepared everything and it'd be a waste to just say nevermind because he said something silly. Like, she can be pretty whimsical, but I don't think she's that petty.