On a multilingual site, an user has permissions to edit only in one language (language A).
Suppose that an object has an archived version in another language (language B).
The user can edit that object and in the "manage versions" he can copy the archived version in language B into a new draft. Then he can't edit that draft, because he doesn't have permission for language B.
I expect that the user cannot copy a language B version, because he has permissions only for language A.