What should I do?

[Sideeffectisgratefulchild]

Hi I've not posted here before. I've bought and sold on eBay for years - big and small things - though had mostly stopped recently due to their new PayPal arrangements.
However my teenage son bought some trainers recently that he then wanted me to sell. I have the receipt - he bought them from the Ni.ke store and then sold them on at a moderate profit.
The buyer has messaged today saying they believe them to be fake and asking for a refund/return.
Now on one level I could accept that and either sell them again or return them (I have the receipt still). But how do I know that he will return them in the pristine condition I sent them in and that he hasn't switched the trainers for fake ones himself?
At the moment I have declined the return and am waiting for eBay to step in in a couple of days.
Other than one negative feedback (for a used pair of shoes that I described perfectly but apparently didn't fit the buyer who paid £3 🙄) I have over 3000 positive feedbacks. But does that mean eBay will be more likely to find in my favour?
I know I haven't done anything wrong but am worried that I will (or my son will!) be out of pocket through absolutely no fault of our own.
Can anyone advise?

So you can prove with the receipt that it was a genuine Nike purchase? Offer to email him a copy of the receipt. Don't worry that he'll see you've made a profit. That's not relevant.

Surely he cannot claim item not as described so that route is closed to him.

I too would be wary of accepting a return. I presume you have a 'no returns' policy.

What is his feedback like - sorry if u mentioned, but I have the attention span of a gnat at the moment.

Finally. The eBay community pages are full of similar type problems so have a look there.

Yes I would not want to have them sent back either as things like this can be well known scams. I would be worried about receiving fakes back too. If you can prove they are real with the receipt and the only issue for the buyer was worrying about fakes then there is no reason with authentication that they wouldnt want to keep them 🤷‍♀️

Yes I can prove with the receipt. He says that that's not relevant - that we must have bought fakes (from Ni.ke store?!)
I said that he could send me fakes back but he sent photos of why he thinks they are fake and then says you can see the same issues in the original photos we sent ie trying to prove that he isn't sending different ones back. So then surely he can't claim that they're not what he expected?!

Logically he can't; but unfortunately Ebay rules let him do that and get away with it as they always find in the buyers favour.
Do you have any way to prove the item he returns is different from the one you sent?

Accept the return and leave factual feedback that just states what happened, then block him. You can't leave negative feedback for buyers but you can be factual.

Just accept the return, that’s all you can do here, unfortunately.

You could try contacting EBay and explain the problem. I've found them to be quite helpful when I've had problems with dodgy buyers in the past. I think it helps that I've had an account for 15 years and have 100% f/b.

I would not accept the return. It might be buyers remorse and they want their money back and those people should not be encouraged.

Are they trainers the latest edition? Can you find and submit photographs from reputable companies websites that show the trainers for sale?

What specifically do they claim makes them fake? ie where on the trainer?

but he sent photos of why he thinks they are fake and then says you can see the same issues in the original photos we sent

So if he could identify the problem with the trainers in the listing photographs why did he buy them? Rhetorical question but worth mentioning in your statement to ebay.