Nested SPARQL queries not being fully rendered

[alexdma]

The entity https://data.mksmart.org/entity/image/19725008660 generates the following query:

SELECT DISTINCT ?p1 ?o1 ?p2 ?o2 WHERE { GRAPH urn:flickr-mklocation
{ { { http://data.mksmart.org/flickr/photo/19725008660 ?p1 ?o1}
UNION
{ BIND(uri("http://purl.org/dc/elements/1.1/creator") AS ?p1)
http://data.mksmart.org/flickr/photo/19725008660 http://purl.org/dc/elements/1.1/creator ?o1 . ?o1 ?p2 ?o2
}
}
}
}

However the JSON renderer only shows the data from the full paths p1 o1 p2 o2, but not those with just p1 o1.