I'd take it now if i got the chance. If there was a piebald fawn last season that got shot, chances are that this one might not make it either. And even if it is a buck, it will take another year or two to grow a decent rack. And i think the odds of a piebald making it through two or three hunting seasons is pretty slim, especially since other people are hunting the same area. If it was a private farm that only you hunted, I'd say let it walk. But with other people hunting the area, i'd say theres a good chance someone else will end up shooting it.