Interesting initial replies. Kinda confirms my suspicions. Now if it was a situation where a bill is for, say $50.50 and they are presented with $55.50, it might well be reasonable to assume the $5 was a tip, but I would think MOST would still try to give it back just to confirm that was the case. Unlike KKs case, they would not be at risk of losing a large account, only the small chance of repeat business. Got to say, it was dumb of me to drop a $100 bill and then overpay somebody else by $50, but not at all surprising they gave it back and saved me much consternation later. Oh and I can highly recommend Barwon Orange cafe in Barwon Heads. Not just for the honesty of their staff, but for the excellent Mahalia coffee they serve and great food too. Daughter and I had very nice short blacks, surprisingly well balanced and low acidity (East Timorese single origin).