Urgent: Help a noob to Twickets!

[Scam]

So, as we cant sell tickets on here I posted some for a gig tomorrow night that I can't attend, on Twickets.

Got a buyer already and my email from PayPal says the below

Dear XXXX

You received a payment of £38.64 GBP from Xxxxxxx
Thanks for using PayPal. You can now send any items. To see all the transaction details, log in to your PayPal account.
It may take a few moments for this transaction to appear in your account.

Seller Protection - Not Eligible

Reversals:
Please be aware that your payment can still be reversed, (e.g. if it is subject to a chargeback), even after you have sent the item to your buyer. Complying with PayPal's Seller Protection and following the trading guidelines on our Security page helps to protect you from things like chargebacks.

I've used PayPal a couple of times to sell on eBay but this has given me the fear.

The gig is tomorrow so the guy will be wanting to collect from my work tomorrow.

Any way I can be screwed over here? Can he reverse the payment once he collects or anything? Can I take the money out of my account to stop it? How come I don't have seller protection?

Thanks!