That's a good definition of the Product Owner... and as an add-on to last post, he's the one that gets the blame when he takes bad decisions. This time the product owner choose to prioritize a quick deliver instead of focusing on requirements, and this was not a happy choice. Luckily, his head has not been chopped and it is not going to be, but surely this taught him something.
Unluckily, the Product Owner is also the one who gets the blame when decisions were good but the outcome wasn't. Moreover, we have to remember that a bad decision is better than no decisions at all, as bad decisions can (almost) always be reversed, and that we firmly believe that everyone is always doing (trying to do) his best.
So what's the point in being a Product Owner? well, it is true that you have to carry the burden of insuccess, but you also are the shining star in case of success. Nevertheless, it is quite difficult to find someone who is willing to play this role when you're transitioning to Scrum, because of that axe always lurking above. Even more difficult when the Product Owner is an external customer.
The only way we have to persuade people is to educate them, showing that we are not looking for a single neck to chop, but we're looking for someone that could help us to reach a truly win-win situation.