I have just received a message from eBay that I find very interesting.  They have updated, among other things, their Buyer Protection Policy.  The way that I read it as it may apply to autographs, if eBay are unable to determine that an autograph is or is not authentic when a buyer files a claim they will "generally ask the buyer to return the item to the seller and will ask the seller to refund the buyer".  They will also reserve the right to get our money back without our even returning the item to the seller.  I have copied the actual language of the message that pertains to the updated eBay Buyer Protection Policy below.

Key updates to the eBay Buyer Protection Policy:

• Simplification. We rewrote our Buyer Protection Policy to make it more clear and understandable.
• Resolution of item not as described cases. We updated the policy to clarify that we carefully weigh all the information provided in cases where a buyer claims that the item delivered is not as described in the listing. If we can't determine from the information we have that the item matches or doesn't match the listing description, we generally ask the buyer to return the item to the seller and will ask the seller to refund the buyer. In addition, we updated the policy to reflect that, if as a seller, you choose not to engage with the eBay Buyer Protection process on an item not as described case, we may seek to carry out a reimbursement from you without asking the buyer to return the item to you.
• Case window extension. We updated the policy to reflect that we reserve the right to extend the period that buyers are eligible to open an eBay Buyer Protection case during which sellers are responsible for resolving such cases (e.g., national emergency, national holidays, and governmental acts). When applicable, this will be communicated via the announcements section of eBay.com. In addition, we will soon update the timeline for opening a case to 30 days after the estimated delivery date. We calculate the estimated delivery date based on the shipping service used and the shipping address. In the absence of information about shipping service, we will estimate delivery date based on average delivery times for each location. We will notify buyers and sellers when this change goes into effect by posting an announcement on eBay.com.