If you check the RDFa markup in the page for OrderDelivered you see it has type rdfs:Property:

<div id="mainContent" vocab="http://schema.org/" typeof="rdfs:Property" resource="http://schema.org/OrderDelivered">

Whereas in the source RDFa file it has type schema:OrderStatus:

<div typeof="http://schema.org/OrderStatus" resource="http://schema.org/OrderDelivered">

Looks like something gets lost/mangled during generation of the published HTML pages.