That''s your assumption. Why don't you sign the message from that address (its like 2 minutes work) and prove your theory? I would if someone called me out for bullshitting while I had tools to prove him otherwise.
it is interesting that he persistently avoids any discussion about address verification. It's somehow easier for him to open new threads and regularly respond to every post, but a simple two minutes for verification and the end of the drama are not on his to-do list.
I believe that sending a symbolic amount (the last four digits of his bitcointalk UID for example) to his own address would be sufficient confirmation that he really manages the disputed address.
I will consider him a troll because apart from senseless arguments and insults, I don't see his true desire to solve this.