Thanks for the discussion. We agreed with the ruling without much argument. I figured it'd be a good discussion though. Couple thoughts:
How can there be no benefit of doubt for the player pertaining to hitting in bounds on the fly but then if there's physical evidence of a mark in the bank there is benefit of the doubt? All the marks could be from a previous round. You can't assume in some instances but you can in others?
Having OB to close to a pin is not a "weak" hole design. Having a basket in OB, that's another story. Creeks with running water should never be casual water. What's the purpose of having any OB then? Nature DOES play a part in every course design. It makes designers take into account numerous aspects of the surroundings. Fairways aren't something we "carve" out, they're something we adapt to within nature. Yes we can place things differently and have a bland hole. I'd much rather be near a creek and have to think about the consequences of a missed putt instead of every green being "safe".