<p>Well, if you talk about something COMPLETELY irrelevant you don't get anything. But they only GIVE you points for something you did well; they can't subtract (or so they say). So even if you misinterpreted the passage, maybe you did have some arguments that do apply or make note of something that was relevant, in which case you will score some points.</p>
<p>But then again, I'm not 100% sure. But for sure, the readers look for GOOD things about your essay that will improve your score...Good luck. :)</p>