Who cares if you contradict yourself? I've worked (too) many years in an industry where the customers expectations often exceed technical capabilities (not to mention their wallets), but you learn ways of blaming them without actually blaming them. "The budget for this project really doesn't have the room for that feature." It was their fault, I didn't take responsibility for it, but I didn't say, "You're not paying me enough to do that.".
At the end of the day, placing blame on customers (or more importantly, informing them they are at fault) is going to cause more problems than its worth. Fundamentally, the quesiton you have to ask yourself is whether it's more important to be right, or to be employed.