Both Mary and Sandra get commissioned to the same murder trial. There are 11 votes guilty and 1 vote not-guilty, Sandra choosing not-guilty. After hours, she still has not changed her vote and Mary is annoyed because her anniversary is that night.
They vote one last time, and this time the 1 not-guilty vote is from Mary. The judge sequesters them for the evening in a hotel and Mary is going to miss her anniversary dinner with Lester.
Lester sneaks into the hotel room and brings Mary caviar and champagne. The next day, Mary presents her theory of what actually happened (pertaining to the ""murder"" on the boat) and the jury agrees and they all vote not-guilty.
Their verdict was the right one, because later the ""murdered victim"" was found on the French Riviera with her husband's best friend, which was stated in a voice-over.