It all hinges on whether or not an eBay auction does generate a legally binding contract. If it does, then the pen now belongs to the original buyer. who fulfilled all of the terms of the original contract. The seller violated the contract by retaining possession, and is now listing an item that no longer belongs to him without the consent of the actual owner. If eBay allows a second sale once they are made aware of the situation, they may well have liability for any loss suffered by the original buyer. In addition there may well be recourse through legal agencies. It all depends on how much time and effort (and potentially money) the original buyer wants to put into this.
It is a legally binding contract (here in Australia anyway), legal being the "problem". The cost of enforcing that right negates any benefit on low value items, especially if costs are not in favour of the plaintiff. I suspect eBays position is sound in that the ownership of the item remains with the seller until proven otherwise ( the old "possession is 9/10 of the law"), if legal action was commenced then the auction would be suspended until the matter resolved.
Regards
Hugh
