Overseas buyer - not as described claim

F&L

I sold an item and posted it the same day - the following day the buyer advised he no longer wanted it and wanted a refund. I said fine, he could have a refund once he returned it. A few days later he advised he'd received it but it was damaged and wanted a refund - the photo he sent showed a nice hole in the item which certainly wasn't there when I sent it but I thought it was easiest to ask him to return it due to paypal siding with buyers.

He then initiated a claim for not as descibed so I clicked on the option he could have a refund once he'd returned it.

The email I've had from paypal says the following:

"The buyer has 10 calendar days to provide proof of posting for the item
being returned. PayPal will issue a refund from your account once the we
can confirm that the item was posted."

Does this mean that if it goes astray I will lose out completely? Should I have clicked a different option i.e. stated I believed the buyer had deliberately damaged the item? I've not had a not as described dispute from overseas before.

Any advice would be appreciated.