I have placed a break point where you mentioned and can see that javax.enterprise.inject.spi.Unmanaged is being returned by the getCallingClassName() method.
At line 54 'names.add(Unmanaged.class.getName());' from what I can see in the debugger the Unmanaged class name does not get added to the names array.
This is what is in names: [org.jboss.weld.AbstractCDI, org.jboss.weld.SimpleCDI, com.ibm.ws.cdi.services.IBMCDIProvider$IBMCDI].