The final decision should not depend on remembering who sounded most certain.

Confidence is loud and easy to recall, which makes it a poor guide once the discussion is over. Hours later what stays with people is tone rather than reasoning, and the person who spoke with the fewest qualifications ends up carrying the room. Certainty is not correlated with accuracy in any reliable way.

Before you decide, write down the reasons rather than the impressions. Ask the people who said little what they think, directly and by name. Then check whether the argument still holds when you cannot hear the voice behind it.