Christopher Connelly, who appears as Saint John Hawke, had appeared in the first season episode "Echoes From the Past", where his character was *posing* as Saint John. But that episode clearly established that he actually did not look like Saint John Hawke at all.
After Dominique deploys Airwolf's cannons in all subsequent exterior shots they are still retracted.
During the weapons demonstration, when Mace is firing the cannons at the ground targets, he uses the thumb buttons on either side of the joystick. (This may be a flipped shot, as at one point Mace appears to be piloting the HX-1 from the left seat instead of the right.) However, during the dogfight scenes with Airwolf, Mace uses the trigger to fire the cannons.
When the thieves are landing at Davsco a close up of the rotor head seen is that of an MD 500, but the long shot shows a Bell JetRanger III.
The thieves use auto-rotation to sneak land their helicopter so they can steal the HX1. Auto-rotation doesn't work the way it is depicted and the thieves helicopter lands like it would if the engine was still running--nice and smooth.