Chi-Hwa Chen is credited as executive director of Police Story...

Executive director is not a official position. This is more "assistant director" than director.

Maybe he was the "eye" of Jackie when this one was front the camera.

Weird that IMDb would include such a credit.

IMDB is like wikipedia, it is the users who make the updates.

If you do a Google search for "HKMDB executive director", you will find many such examples in the history of Hong Kong cinema.