The "burglar" attacked him in spite of him having a sword in his hand, and retreated and then came back multiple times. Being a Briton of the current generation, our hero was doing his best not to hurt the criminal:
I was using the sword to block the blows, while also feigning attack. I was terrified, but I was also very aware that I probably shouldn’t really hit him with the sword; that I should act proportionately. The problem was, I didn’t know how far he was going to go – I don’t think he knew, either.... I started thinking that any moment he would realise I was not trying to hurt him. Then what was I going to do? I was exhausted.It worked, which satisfies the dictum that 'if it's stupid and it works, it's not stupid.' The non-sharpness of the sword and the excessive defensiveness of the combat kept him out of trouble with the law, too, which is a real concern in Britain today.
Then, to my relief, he just took off. I was walking slowly back into the house when I heard him behind me. I turned to see him running at full tilt with his arm raised, ready to strike. This was the only time I used the sword as a weapon, swinging at his chest while raising my other arm to block his blow. I got a cut arm and he was injured in the chest – not seriously, because the sword was blunt. Then he was gone again.
The 'aggravated burglary' charge got the crazed assailant a whole three years, which under British law only half of which can be served behind bars and the rest on some version of parole.