If the only way he could have this cat for a pet was to de-claw it, then I am totally against it.
This animal is now disabled for release and must be kept by someone.
(Think of de-clawing as having the first joint of your fingers and toes removed)
You're absolutely right. No declawed cat of any kind should ever be allowed to roam free. They have only their teeth, but they instinctively try to use their missing claws for hunting and defense.