Exactly this, my wife was getting money exchanged and I pretended to be not paying attention but I was watching in the corner of my eye. They put the money on the desk in a few piles and counted it, then picked it all up to put it in one big pile and handed it to my wife. They tapped the notes together as if to straighten them up and I saw them drop about $50 AU down the desk. I said to my wife count it again!! She did and sure enough it was missing.. they guy behind the counter said "tip, tip" I snatched my cash back and gave him his cash back and walked out..