If I fire the query below and then loop over the resultset using NodeIterator.hasnext() / NodeIterator.nextNode(), I get a java.util.NoSuchElementException at org.modeshape.jcr.query.NodeSequence$SingleWidthBatch.getNode(NodeSequence.java:1979)
at org.modeshape.jcr.query.JcrQueryResult$QueryResultNodeIterator.nextNode(JcrQueryResult.java:292)

Edit: same happens if using UNION, INTERSECT works in this case but only because it returns an empty resultset. So I guess it always happens on non empty set

Code used to loop:

NodeIterator nodeIterator = query.execute().getNodes()
while (nodeIterator.hasNext()) {
              nodeIterator.nextNode();
            }

Query code:

SELECT BASE.* from [nt:unstructured] as BASE  

JOIN  [nt:unstructured] AS REF ON ISCHILDNODE(BASE,REF) 
JOIN [nt:unstructured] AS REF2 ON REF2.[jcr:uuid] = REF.[jcr:uuid] 


INTERSECT

SELECT BASE.* from [nt:unstructured] as BASE  
JOIN  [nt:unstructured] AS REF 
	ON REF.[jcr:uuid] = BASE.[jcr:uuid]