I sent him a PM regarding this on 31st August and I didn't get an answer yet. So, Let's discuss it publicly.
A simple PM reply stating that the address they send btc to is an exchange or a corporative address (if something of that exist), would have solved this problem. Now, you have made it public, I believe he will have to reply. Maybe he is waiting to see the forum reactions first before he will clear the air.
I disagree. Nobody owes you an explanation in such matters. If you can't make your case using only post history + blockchain, then you don't have a case.
Privacy-invasive behavior should be discouraged.
This type of inquisition is the lowliest approach to merit farming.