Unless the drive is shared on the domain, it shouldn't be an issue. But other options would include not installing the HFS+ driver from Boot Camp, preventing Windows from being able to read the partition at all, or having the domain admin alter group permissions to prevent access. When part of a domain, you can't do this sort of thing yourself, unless you have the appropriate access level within the domain. So assuming you're not the one admining the domain, and the person who is isn't an idiot, you won't have that kind of access.