Buyer claiming item is fake after leaving +ve feedback.

[Charmingbaker]

I sold an item of clothing this weekend, buyer paid £30 for it and left positive feedback on Wednesday. The buyer has emailed me today saying the item is fake.
Now I know it is not fake. It was a jacket I bought for my now DH when we first started going out. I bought it from Harrods in the late 90s (I stated the department and year purchased in the listing). We had both just started our first proper jobs post uni and bought each other a treat (I know this detail is irrelevant, but it is why I remember so clearly where and when the item was bought).
My query is, can the buyer do anything now they have left feedback?
The buyer emailed me today stating the label says made in China so the item is fake. I did a quick google search and came across lots of threads that said this brand does make items in China.

[IncognitoIsMyFavouriteWord]

No just keep replying with the facts.

If she opens a case state those facts to eBay too.

She has to prove it's a fake.

[LavenderGreen14]

them having left feedback means nothing

if they open a case ebay will prob tell them to return for a refund

[balenciaga]

I'd have thought incognito is right, they would surely have to prove it somehow

grr how silly for a 30 item which is clearly real, they are obvs trying it on

[Charmingbaker]

Thanks, they haven't asked for a refund or said they will report it, just messages saying I've conned them and they've learned a lesson. I have just replied each time that I bought it myself from the labels department in Harrods and when. I'm thinking the buyer was hoping I hadn't bought the jacket new and was hoping I'd give them a big discount. The buyer has now sent pictures of the item to the label, which is fine by me.