Calling QueryResult.getNodes() produces exception

Running a test application I have encountered an exception. I have seen it only once for now so it is not happening consistently. Calling QueryResult.getNodes() resulted in:
javax.jcr.PathNotFoundException: Unable to find "{}myfile.txt"; lowest existing path is "/"

I don't see such exception anticipated in the JCR 2 API. Please see https://hudson.qa.jboss.com/hudson/view/SOA-Release/job/soa-modeshape-ddl/93/artifact/jbosssoa/jboss-as/jdbc_conf/mssql2005/testapp.html or MSSQL2005 result on https://hudson.qa.jboss.com/hudson/view/SOA-Release/job/soa-modeshape-ddl/93/artifact/test-output/Groovy%20Test%20Suite/index.html

Also same hudson build contains server log (https://hudson.qa.jboss.com/hudson/view/SOA-Release/job/soa-modeshape-ddl/93/artifact/jbosssoa/jboss-as/server/production/log/server.log).