Dealing with schedules for people and not understanding each persons personal motives behind their reason for volunteering can be unsettling. Finding out the dynamics and personalities time schedules and care schedules is a process that needs to be dealt with. With a mediator that knows how to mediate properly , will take time with the group to know the people and to work with them all and not just let one person take over without knowing the person motives, because each person in the group has his own motive if they are not cohesive with working as a team. I am sorry you were blind sided sometimes a mediator has no idea what to do right and doesn't take the time to know the personalities of the group and makes bad decisions. That sounds like what happened to you.
Did you think it was a good mediator? If not ask for help from the source where the mediator was elected to mediate and give you honest concerns.
NOT all people come to a meeting about care giving with honest desire to be a honest and true team player. Motives behind their being there should be the mediators concern to pay attention to. Good luck with this. I also have to look at my motives in my actions also. I may not be sharing properly.