That's his excuse to save his "face". If you're a coward and you lose an argument, then you say were joking and make the other persons seem like a fool. That's what he tried to do.
In school. English was the primary language used to impart knowledge there. Text books, exams, interactions... all English. This continued throughout college too. Then I joined a call center and had 1 month of voice and accent training. The icing on the cake was about a year of call-taking.
Don't you have any other movies with you that you haven't seen yet? Either cos it didn't interest you much, or that there were movies more interesting to watch. This would be a good time to watch such a movie.