It sucks that he is still medaling in your project.
I can see why PG Classics called him though. Yes, Brian called initially to inform PG to ship the panels to you since the build would no longer be in his shop when they arrived. You then called PG to confirm they would still be shipped to your address. All good so far. I think the problem was when you proactively aired the dirty laundry about Brian. That probably raised a few questions for PG in terms of one party claiming the other ripped them off once the item was delivered. That could result in PG Classics needing to provide a second set to the other party when only one was paid for. I can’t fault PG for making another call to Brian to confirm (since he was the one who originally placed the order) and there was now one very pissed off person (you) involved.