The video gives a glimpse of Williams' prowess as a leader (he finds a way to individually pump up a very large percentage of the 49ers' roster during the pregame period), and also shows that he was clearly not himself late in the game.
At around the five-minute mark, Williams can be seen wearing black tape over his cleat on his right foot. He moves around very gingerly for the duration of the video. When the 49ers kicked the game-winning field goal in the fourth quarter's final seconds, Williams was sitting on the offensive line bench alone, while the rest of his teammates were on their feet watching the attempt alongside the coaches and various personnel on the sideline.