Ching Siu-tung
Johnnie To stated that "Tsui had lots of ideas [for "The Big Heat"], changing the script all the time, but three days later he would come up with something totally different." To went on to describe that the violence in the film originated from Hark's suggestions, and that it was "a very difficult project" To noted that he was brought in after another director was unable to satisfy Tsui Hark. To also stated that he did not complete the film, but that Tsui Hark completed it with Ching Siu-tung shooting some scenes.