If item is refused or even if buyer gives incorrect address and item is returned to seller, buyer will with certainty lose the PayPal dispute. All you need to do if under review is give PayPal a call now and they will be able to view the tracking details and close dispute whilst you are on the phone. Even if item has not yet reached the recipient yet (either because in transit, RTS or refused) PayPal will be able to find in your favour. Have done this before with no issues, but may depend on who you are speaking with at PayPal.

If buyer than attempts to do a bank chargeback you will have all the proof you need to be covered under Seller Protection and will not be out of pocket (except $15 charge by PayPal which you can call and ask to do a one-off waiver of this fee)