He wrote something about his wallet needs a verification from his smartphone. Does Armory support 2FA maybe? It might be an explaination for why the coins didn't move. Of course only when you want to take his story.
if the private keys were compromised, which, if this story is true, they should be considering the signed message linked in my quoted post, the hacker wouldnt need any sort of 2FA to move the coins. the private keys would give a hypothetical hacker full control of the coins regardless of whatever security measures armory provides.