Related Clues:

• Prove oneself fallible
• Affirm one's humanity?
• Do math incorrectly, e.g
• Make an incorrect choice, e.g
• Miss an easy spare, say
• Not be right
• Require a 110-Across, maybe
• Be amiss
• Miss one's exit, say
• Make 1-Down
• Make a wrong decision
• Jump the gun, e.g
• Muck it up
• Exemplify humanity, say
• Flub it up