Related Clues:

• 'Mea culpa'
• “Oops, I blew it”
• “Oops, I goofed!”
• "Oops, I messed up"
• "Oops, sorry!"
• 'Oopsie!'... and a hint to the ends of 18-, 25-, 39- and 50-Across
• "I'm to blame"