Listening to a proposal and offering criticism may feel like a contribution. Depending on the critic’s experience and role in the project, criticism may be constructive.
If you offered criticism, you’re off the hook. If the project is successful, you put your thumbprint on it somewhere in its development. If not, you tried to warn everyone.
Speaking up with a critical comment may feel courageous in the moment. But, offering a solution a true act a bravery.