Those caddies at TOC don't like us Aussies. They think we're cheap. I remember when I played there. I didn't use a caddy but when the caddies for the two of the other guys I played with found out I was Australian (and not a New Zealander which they thought I was) I got the "Oh, you're an Australian. We don't like them here." Immediately, I guessed that it was due to the tipping thing. I spent the last 5 holes trying to explain why Australians don't tip, as it's not part of the social culture in our country. For that matter, using caddies isn't either (nor is the high price of golf). I suggested it probably wouldn't be a problem if there was more pre-booking notice of the expectations on golfers as to what is the accepted practice. But I think it fell on deaf ears then (and looks like nothing much has changed since). Anyway, after one caddie spent the 5 holes telling me how customers should tip well for good service, he spent a good deal of time apologising to his golfer/client for losing his US Open towel somewhere on the course. He was lucky the client was a good bloke and tipped him anyway.