Why now? I suspect it was someone in a call centre applying the rules and procedures rather than using judgement. If one of the grounds for your dispute is that the item is a fake, it will put in chain a process no doubt designed for fake watches and pirated software. The person handling the claim will have a set process to follow which he probably isn't allowed to deviate from. Perhaps he should have escalated it to someone higher, but if he was following the procedure perhaps he didn't see the need.

The claimant says it's not what the label says it is. Perhaps an expert has confirmed it. In the world of dealers that's no big deal, unless there's a deliberate attempt to defraud, but it's possibly all it would take to trigger Paypal's "destroy it if you want to get a refund" response.