Clarification: Example 45, expansion of interest.name

In Example 45, interest.name expands to http://schema.org/name despite interest having a property-scoped context with vocabulary set to http://xmlns.com/foaf/0.1 (and foaf defining a property name.)

Is this because the domain of foaf:interest is foaf:person and foaf:person is not in the domain of foaf:name, (but e.g. of foaf:first_name)? This seems illogical, since it requires the JSON-LD processor to understand RDF schema (at least), everything else up to now has been self-contained.

I think actually this is because @vocab acts as a fall back for terms not defined elsewhere (here name in the outer @context) but perhaps a notice would be helpful.

Start with Example 45 in the linked JSON-LD Syntax specification and trace how interest.name is expanded using the outer and property-scoped contexts. Clarify the fallback behavior for @vocab and explain why RDF schema domain information is not required; done means the example or surrounding text answers the reported question.