The caddie should refuse to carry anyone who insists "its my bag you carry it".
Adam,
I'm confused. Isn't that what a Caddie does?
I could fill the band width of stories of what people carry in their golf bag.
Maybe, if one only has the perspective of caddying as a youngster, Shivas' attitude will prevail. But, since these caddies are not kids anymore, and they usually carry double, having the proper balance and controlling exactly what is carried is very important. Don't discount the need for proper working pop out legs, either.
Honestly, If the client is going to refuse the first advice of the day, it's going to be a long day and will likely end up with the attitude Dave has towards the caddies at PB. That's why refusing the loop is the best move the caddy could make.
There is the famous story about the guy in Jamaica, who forgot to remove his dive weights that he stored in his golf bag for the plane ride after his previous trip in Hawaii. The caddy dropped the bag on the fifth hole.
I personally had a real doofus with a Louis Viton golf bag complete with gold trim. When I wanted to swap his bag he resisted. No problem. I told him that if I carried his bag around Pebble, I would need to take a week off of work.
BTW, That's not all caddies do, unless that is all you want then to do. And if that's all you want out of a caddy, why take one?