Clearly describe behavior of PUT for structural and navigation properties

Would it be fair to assume that because the section 8.5.4 uses the word "MAY", that if a client does not provide any bindings for navigation properties when using "PUT", the relationship(s) should remain unaffected?

The JSON spec section 8.5.4 states:

"For update operations a bind operation on a collection navigation property adds additional relationships, it does not replace existing relationships."

The protocol spec section 11.4.3 "Update an Entity" states:

"Services that support PUT MUST replace all property values with those specified in the request body. Missing properties MUST be set to their default values."

Is that only meant to apply to structural properties (if so, perhaps we should state it explicitly)? Because otherwise, it seems to conflict with the JSON section 8.5.4.