Jet Li badly damaged his knee when Wong Fei Hung jumps out of the tea shop using his umbrella. For this reason a lot of the final fight was performed while Li was in plaster, meaning he had to be doubled for some of the moves. A lot of the shots are from the waist and above, to hide his plaster.
Wong Fei-hung was a famous practitioner of hung gar kung fu, although the techniques Jet Li uses are mostly of the long fist method and tai chi.
Jet Li's voice is dubbed in post-production because he is not a Cantonese speaker. In fact, he spoke in Mandarin entirely during filming.