I have offloaded a passenger before based on the CM’s opinion/ reports and on reflection thought that a different CM would have been able to keep things calm and under control. The Captain is kinda hamstrung though because if you don’t back up your CM you have a different issue to deal with. Also, it is rare that the Captain can make their own assessment. Probably worth pointing out that I’ve offloaded others based on CM reports and it was definitely the best option.