In the rape scene recreation with a pistol you can see how the bad guy is already grabbing the woman in her car. But in the next scene where she grabs her pistol and is about to shoot the bad guy is already more away and is not holding her at all.
In the closing scene, Derek Savage knocks on his own glass table top to simulate the sound of the "mailman" knocking on his front door.
At one moment Derek is seen typing on his computer but it is clear that he is not actually typing anything.
The poster of this movie is visible in the background several times. Sometimes it is said "Gun Self-Defense for Women" and sometimes it is said "Gun Self-Defense for Ladies", which is because Savage renamed the movie later and re-released it. Also when naming the movie Savage keep switching between the two titles.
When using the pepper spray it is visible that the woman is using real spray, based on the color, but when the attacker is shown it is clearly visible that this is pure water he gets sprayed at. It doesn't look similar to pepper spray.
Midway through the end credits, the sound, picture, and scrolling credits "glitch" out (consistent with the film being shot, edited, and distributed through digital formats) before a stock effects shot shows a film reel breaking in a projector and burning.
During the movie the CCW instructor, as well as Derek himself, mentioned several times that it is important to keep your finger off the trigger when not shooting. However in many scenes of the movie, especially in the desert shootings, Derek and the woman are seeing holding the guns with the finger on the trigger.
During the shooting sessions nobody is wearing any ear protection, eye protection, or any other kind of safety protection to protect your body from the noise and from the bullets. In real shooting sessions all this equipment is usually in use.
Despite his given status as an "expert" on gun safety and usage, Derek Savage's suggestion in one of his scenarios that a responsible and trained gun owner should leave an unholstered handgun in an empty car passenger seat while out in public would be tremendously careless, unsafe, and improper handling of a firearm.
When introducing the subjects of the movie Derek Savage mentioned that he will teach how to clean your weapon. This is not even mentioned in the entire movie.