Committee chair problem

I’m not giving too much detail for obvious reasons.
The Chair of a committee I am on seems to treat the organisation as his own property.
The Committee recently needed to resolve a particular issue and took a decision. There was no vote. Now the Chair has subsequently overruled the committee decision and issued instructions to resolve the situation differently.
I have no particular view as to whether the Committee’s decision or the Chair’s decision was the better way, but I do think the Chair had no right to overrule in this way.
Fair enough, if there had been a vote with no majority either way, the Chair would have had a casting vote, but he has acted outside of the Committee.
I feel very uncomfortable about this. It is realistically too late now to alter the plan, but I am not happy to just let this situation go. What would you do?