My post was only based upon guesswork, Cazzz, but it's a standard trick in psychological testing to try to draw a respondent's attention away from one possible answer by making them concentrate on an alternative.
By mentioning a particular physical characteristic of the aggressor (i.e. that he's wearing, or at least in possession of, a bowler hat) it makes the person reading the question think about the attacker, rather than about their own physical response to the attack.