following happened to me while I was searching for the ah-bid-exploit.
I bid on an Item and changend my systemtime so the auction I bid on was displayed like 1min left. After the auction was displayed as expired I got my gold back and bid again on the expired auction. Then I got my gold back a second time and after changing my systemtime to normal I was still leading on that auction. So I payed twice, got both back and was still leading in the auction.
The first time I thought it was just a bug in my brain but after trying different things to find the ah-bid-exploit it happened a second time. After this I tried to replicate this for some hours but it didnt work. The main thing is to get your gold back the first time without a new bid on that item.
Sometimes I changed my systemtime while d3 was running and switched ah tabs and sometimes I closed d3 before. I dont know in which case it happened.
So I wasnt able to do it again but I just want to let know you. Maybe you want to play around with this, Im going to work now.
I also heared the ah-bid-exploit is allready hotfixed, maybe it was similar to this and it is hotfixed too.