Is there any chance for Person F to withdraw the bid after all bids are opened, as no winner ... has been declared, and under what circumstances one would change the answer. ... a bid cost of $20...

Is there any chance for Person F to withdraw the bid after all bids are opened, as no winner ... has been declared, and under what circumstances one would change the answer. ... a bid cost of $20 million, but Person F comes to know that all other bids are over $25 million