Sorry, no I don't know why he was called Karr. I do know that there were a number of them named Hezekiah, and it is most likely a nickname, or way of telling each apart. I know from talking to older relatives that many had a way of saying a person's name, that didn't even sound like their name. As an example, my daughter's name is Sara. All of my older relatives call her Sally. And none of the pronounce my name the way it is supposed to. They pronounce it Shee-Lee.