I occasionally have students call me "sensei" as opposed to "coach" or "professor" or "Tony". I don't chide them for using the wrong language. I know what they mean. It appears Mr. Di Rauso is teaching his own art (MAKA Fighting System) which is an eclectic blend of arts from different countries, so he's free to choose whatever honorific he feels appropriate for instructors of that art. As far as the video itself, the setup shown (as in many of his other videos on YouTube) seems to rely on the idea that he is much faster than his opponent. That may often be the case for him, but isn't likely to work out so well for his students.