There is a check in the subordinate orphan detection that not only checks for matching gtrid but also for matching subordinate name. This will not match correctly for an intermediary node. E.g.
a->b b->c

When b scans c the xid it gets back will have subordinate name of c, b will look in its object store and match the subordinate on gtrid but the subordinate node ID in b subordinateatomicaction will be "b".

This check is actually superfluous anyway. We already know that the Xid returned from c was for b because of transport level checks.