Related Clues:

• Hits a sour note, say
• Is off target
• The woman's vulgarly mentioned slips
• Goes off the mark
• What autocorrect often does, in effect
• Goes off-target
• Goofs but good
• Decides incorrectly
• Is not mistake-proof
• Terrorist occasionally makes mistakes
• Answers incorrectly
• Mispells a word, say, like in this clue
• Bungles it
• Makes mistake
• Isn't impeccable