A very solid job from Marie.
Consensus is the fruit of team work. You have a better design to finish the project, and you have the related parties back the solution. It would have been perfect if you had not had your boss excluded from the decision-making process, a fatal mistake that one should avoid at all costs. Even if the initial design was not from your boss, but your team mates or subordinates, it is lack of mutual respects to overthrow it without communicating.
I don't think it is fair for your learning the lesson at such high expenses. Mais c'est la freaking vie. Move on.