But I didn't make it that easy for you -- in my version of PH, there is no direct communication; Omega only goes by your conditional behavior. If you find this unrealistic, again, it's no different than what natural selection is capable of.

I find it totally unrealistic. And therefore I will totally ignore it. The only realistic scenario, and the one that natural selection tries out enough times so that it matters, is the one with an explicit spoken promise. That is how the non-omniscient driver gets the information he needs in order to make his rational decision.

But my point was that the revealed preference does not reveal a unique utility function.

Sure it does ... As long as there has or has not been an explicit promise made to pay the driver, you can easily distinguish how much the driver gets due to the promise from what the driver gets because you like him.