If I had steps I would yell something about sparta and teep him in the chest.
Then ask him if he was scared.
I'd treat them like I do Mormons. Invite them in and have an in depth discussion on why my belief system could never be shaken by a blind adherence to years old dogma that was possibly mistranslated and most definitely misunderstood. I'd go on to challenge their belief system and their first utterance of "you just have to have faith" earns a sharp rebuke and a clear path to the door.
You know if somebody came to my door and ask me that question, he would be seeing the business end of my .45. I am getting to old and sore to slap these punks around. But you still did a good job.
I predict that this poor deluded soul will scurry back to the dojo with his tail between his legs. He will train for awhile with Colin in the back of his mind and the question of 'How did he DO that?' in his head.
Eventually, he will come to understand that GKR is awful.
I believe you quite literally knocked some sense into him, Colin.
This is why you should always have hash cookies to offer.
It is only polite.
He will spend a good hour screaming at a BOB body bag, poke it a few times with his deadly point spar strikes, and drink magic KI water to realign his chakras and ward off any future bad luck.
He will then spend the rest of the night at a local pub drinking, crying, and trying to pick up 18 year olds with what he percieves to be clever lines about deadliness in combat.