A DESCRIPTION OF THE PROBLEM :
The sample has class HelloImpl extends HelloPOA. But the point of the POATie model is that Impl do not inherit from POA and only implement the Operations Interface.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The sample should be
class HelloImpl implements HelloOperations
ACTUAL -
class HelloImpl extends HelloPOA

URL OF FAULTY DOCUMENTATION :
http://docs.oracle.com/javase/8/docs/technotes/guides/idl/jidlTieServer.html