Yes, decisions must be made under uncertainty, because we don't ever know the exact outcome. Sometimes, even when acting rationally using available evidence, a decision winds up having negative consequences. Them's the breaks in our uncertain reality.
If a group of people collectively make a decision that is not consistent with evidence and their ethical system, then they are not making decisions correctly. I don't think anyone here is debating that decisions can be incorrect.
If a group of people collectively make a decision that is not consistent with evidence and their ethical system, then they are not making decisions correctly. I don't think anyone here is debating that decisions can be incorrect.