Changes are not properly rollbacked after a bulk operation involving classes that use joined-subclass mapping

I have a Location class on which two other classes "depend" (Contact and LocationTransaction).
When I want to delete a Location Object I use bulk update operations. First I delete the LocationTransactions
connected to the Location object and then I delete the contact objects connected to the location object. Finally
I delete the Location object itself. At the end I simulate that something went wrong and trigger a Rollback.
After the rollback I would expect that none of the objects that I tried to delete was actually deleted. However,
all the LocationTransaction objects are missing from the database after the rollback. Since the other objects
are rollbacked properly I figure that the problem is connected to the fact that LocationTransactions is inherited
from Transaction and uses joined-subclass mapping which is included in the test project in the attachment.

private static void doTest() {
final Session s = sf.openSession();
final Transaction tx = s.beginTransaction();
try {
Location l = (Location) s.createQuery("from Location l where l.name = 'l1'").uniqueResult();

final Query deleteTransactionQuery = s.createQuery(
"delete from LocationTransaction lt " +
"where lt.location = (:location)");
deleteTransactionQuery.setParameter("location", l);
deleteTransactionQuery.executeUpdate();

final Query deleteContactQuery = s.createQuery(
"delete from Contact c " +
"where c.location = (:location)");
deleteContactQuery.setParameter("location", l);
deleteContactQuery.executeUpdate();

final Query deleteQuery = s.createQuery(
"delete from Location l where l = (:location)");
deleteQuery.setParameter("location", l);
deleteQuery.executeUpdate();

//s.delete(l);
throw new RuntimeException("test");
//tx.commit();
} catch (Exception e) {
tx.rollback();
System.out.println(e);
} finally {
s.close();
}
}

Please contact me with any further questions.
Thanks for the help.