When the project deadline loomed, the second guesser kept suggesting changes that only delayed progress.

Don't be such a second-guesser when we try something new; your hesitation holds the team back.

Even after the plan succeeded, the second-guessers kept pointing out minor flaws as if they had a better solution.

Even when a decision is made carefully, second guessers often focus on what could have gone differently instead of supporting the team.