error delivering without team member review

We have a requirement that code delivery must have a Review by a team member.  Yesterday, someone got a non-team member to review and then attempted delivery, instead of a nice error, he got this:
"internal error occurred during Computing Team Advisor Details".
When he attempted to find out what requirement wasn't met, he got a null pointer error.  After getting a team member to review, he got past this.  However, we are wondering what caused the NPE and if there is a fix available?

The .metadata/.log file ends with:

!ENTRY org.eclipse.core.jobs 4 2 2013-07-03 15:30:06.847
!MESSAGE An internal error occurred during: "Computing Team Advisor details...".
!STACK 0
java.lang.NullPointerException
    at java.lang.String$CaseInsensitiveComparator.compare(String.java:53)
    at java.lang.String$CaseInsensitiveComparator.compare(String.java:38)
    at com.ibm.team.filesystem.internal.rcp.ui.workitems.deliveradvisor.RequiredWorkItemApprovalDetailProvider$RequirementFailureComparator.compare(RequiredWorkItemApprovalDetailProvider.java:89)
    at com.ibm.team.filesystem.internal.rcp.ui.workitems.deliveradvisor.RequiredWorkItemApprovalDetailProvider$RequirementFailureComparator.compare(RequiredWorkItemApprovalDetailProvider.java:1)
    at java.util.TreeMap.compare(TreeMap.java:1188)
    at java.util.TreeMap.put(TreeMap.java:531)
    at java.util.TreeSet.add(TreeSet.java:255)
    at com.ibm.team.filesystem.internal.rcp.ui.workitems.deliveradvisor.RequiredWorkItemApprovalDetailProvider.getFailedRequirements(RequiredWorkItemApprovalDetailProvider.java:204)
    at com.ibm.team.filesystem.internal.rcp.ui.workitems.deliveradvisor.RequiredWorkItemApprovalDetailProvider.appendProblem(RequiredWorkItemApprovalDetailProvider.java:114)
    at com.ibm.team.filesystem.ide.ui.process.AbstractSourceControlAdvisorDetailProvider.createDetailText(AbstractSourceControlAdvisorDetailProvider.java:95)
    at com.ibm.team.process.ide.ui.advice.AdviceElementDetailProvider.getDetailText(AdviceElementDetailProvider.java:128)
    at com.ibm.team.process.internal.ide.ui.advice.TeamAdvisorView$8.run(TeamAdvisorView.java:527)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)