Did anyone warn that employee that they were considered to be abusing the policy? If not, then that's horrible, and I won't blame that employee at all. If so, then why not count how many days of vacation that employee took before it was considered abuse, and just set that as the vacation policy?
Yes, agreed. If you have unlimited vacation it shouldn't really make sense to talk about someone "abusing" the policy. You might say that someone takes so much vacation that they don't actually contribute any value to the company, that would make sense to me. There are lots of ways of failing to contribute value, and that would be one of them.
