Do seller need to refund anyway when an INR case is opened by buyer?

[mypaperstuff]

My question is : what is eBay's suggested best course of action for the seller in this situation?

An eBay seller sell an item, ship it using a parcel service, uploading a valid tracking number. Then, some paperwork detached from the box during shipment so it doesn't make it through to the buyer. The tracking show that the item is stucked "en route" but the buyer receive a letter from postal service apologizing for a parcel lost in the mail (due to paper detached from the parcel).

Should the seller :

1. Quickly refund the buyer, and then turn to eBay to get is money back (since valid tracking is uploaded - picture of the original invoice proving the tracking is valid).
OR
2. Apologize to the buyer, explain the situation but not issue refund, instead asking the buyer to simply wait for eBay to issue a refund under buyer guaranteed satisfaction policy - since valid tracking number was provided.

Thanks,

[busybeas_books]

Something is fishy here. Can you get a copy of the letter the buyer received?  Was it a physical letter or an email? What exactly was "the paper" missing from the package? There must be enough info left on the package to be able to contact the buyer.  If so, then why not just deliver it.