In section 8.2.2,

Protected property members can be accessed only within their declaring class and classes derived from their declaring class, and a protected instance property member must be accessed through an instance of the enclosing class

it does not mention accessing through a sub class of the enclosing class. the explanation paragraph later on states it, but for the sake of completeness we should add it, to be

Protected property members can be accessed only within their declaring class and classes derived from their declaring class, and a protected instance property member must be accessed through an instance of the enclosing class or a sub class of the enclosing class.

Related to #700