Well, that's just it - you are not supposed to be able to guess which of the three will get the job. :) I suppose they are trying to say that no matter if you are nervous, normally calm or overly unperturbed, at the end it would matter how fluent in English you are.
What's interesting is that you are perceiving the guy as a 'slacker' :). He's simply trying to project confidence. Perhaps even trying to convince himself how unworried he is about the outcome of the interview.