Actually he didn't say 'Do you know who I am ?' to the bloke he hit. He said 'Who do you think you are?'. He's very lucky to have got off as self defence is very difficult to prove in court, especially when you admit to throwing the first punch. I once was jumped by two blokes out for trouble. I defended myself very effectively and certainly didn't throw the first punch, however I ended up getting charged and convicted of assault.