Plus ebay would pull theauction... Strictly speaking this would be copyright theft as posession ahead of release breaches that terms of licence screen we all ignor but cant fastforeard through.
Huh, hadn't considered that. So if I had a legal copy ahead of the release date, I could get my ass in the fryer for reselling it, even though they're the ones that fucked up and released it early?
No, First Sale Doctrine
applies here. Once you've bought a physical good, the copyright owner can't prevent you from reselling it. The fact that the person has the Blu-Ray before he should is immaterial; the copyright owner got their money when the sale was made and the product is no longer theirs to control.
That's not to say that eBay wouldn't pull the auction. They shouldn't
because the seller isn't doing anything illegal. But one individual seller versus the BBC? Yeah, the conclusion here is foregone.