Buyer bought a wildlife camera system. Then a few days later returns it stating it doesn't works. Upon return, we tested the camera and found out it was in perfect working order.

So either the buyer changed his/her mind after a remorse purchase, or didn't had the technical skills to operate it. In any cases, buyer used a false "camera not working" reason on eBay, so he/she can return it without paying any return fees. Buyer blocked now.