A high-rep user recently closed his account, with no effect on my rep. (I am sorry to see him go.) I know that he gave me at least several upvotes and at least one acceptance. When low-rep users close their accounts, the upvotes they awarded are negated. I've seen a few small drops in my rep because of this.
What is the dividing line between a low-rep user and a high-rep user in negating/not negating upvotes when his account is closed?