When Peter and Carter are at the bus stop, there's a sign behind them that reads 'Yes Were Open', where the apostrophe is missing in 'were' completely changing the word from we're to were.
When Peter talks to the "Naught Flapper Girl" voting, he says, "Go ahead, vote for Taft." Taft ran for President in 1908, 12 years before women had the right to vote.
Male gymnasts do not use the balance beam.