(At around 54 mins) When Seven fights with his amnesiac master (Wong Fei-Hung), the former tries to imitate the behaviors and fighting styles of the villains who have fought with Wong in previous installments (i.e. to help his master to regain his memory). The two villains being imitated were Iron Robe Yim and Commander Lan from Once Upon a Time in China 1 and 2 respectively.
In the fight scene between Wong and the bandit leader in bar, the bandit's head goes through the wooden table and Wong flings it in the air and there's sound of punch, whereas there's no punch.