The word "detective" is misspelled as "dectective" twice during the end credits.
Several characters have moustaches that are clearly pieces of tape with hair stuck or drawn on.
Obvious use of stock images and freeze framed footage over a chroma-keyed Cade Altair.
After shooting two goons dead, Cale Altair picks up two of the used artillery shells and takes them with him. When a gun has just been fired, its artillery shells would be too hot to even touch.
Certain characters routinely reiterate their dialog, twice.