My driver finished 1st yet I’ve failed to meet the Chairmans expectation?

The Chairmans expectation is based upon the teams overall finishing position for the weekend. It’s entirely possible to win a race and fail this expectation. For example if you have the expectation for your team to finish second at a race weekend, if one driver finishes 1^st and the other finishes last then you would likely fail the expectation as there would be other teams earning more points in total than your team.