Kane and Dare. That's a pretty big typo, right? By goof up do you mean he intended it to be Dare but you guys hadn't worked out rights issues to Dan Dare or something. Or that it was always intended to be Kane and he thought the old Marvel character's last name was Dare instead? Or was it really just a typo?
The old Timely character Captain Terror was Dan Kane. But after researching it, Jonathan misremembered it as Dare, wrote it that way, and I trusted his script and didn’t double-check it again. Always intended to be Kane.