This is offspring of
CXF-4816 ( cause, since it brought impl processing ) and CXF-5665.
If there is a 'placement' attribute present in Policy - regardless of it being a standalone declaration in service implementation or part of @Policies group, there will be duplicate declaration of policy reference. Attached is patch with testcase mod to show problem.
3.x is possibly affected as well.
NOTE: I cant assign 3.x and component since JIRA throws "Does not exist"