MacGyver catches a shotgun cartridge in his right hand. Then the angle changes and he's holding it in his left hand.
When Pete shows Charlie and MacGyver the location of the Victoria to Typhoon Harry, the silhouette of the storm is more reminiscent of a tornado rather than a tropical cyclone.
When moving from the balcony to his apartment's interior, MacGyver's shirt changes color.
Despite the dozens of failsafes and backups that any nuclear plant in the U.S. has, a couple of bullet shots not only cause the reactor to go into meltdown, but damage the safety controls intended to stop the meltdown.
Amy explains that they'll die several minutes before the sludge get to the waste disposal chamber, because of the extreme heat that precedes it. However, they exit from the chamber and the sludge pours in immediately as soon as they leave.
When Quayle is flipping through the security cameras he looks at the room where Mrs. Chong and Pete are. Pete disappears and then reappears when he flips back to the room again.
The alarm reset button is on the top of the clock, but is later on the bottom.
Pete is shot in his left arm; however, later he is shown with his right arm in a sling.
MacGyver has an aversion to guns, but despite the fact they knock three of Axminster's armed mercenaries out, Harry never takes any of their guns. He's clearly comfortable using guns: there are several mounted on the walls when MacGyver first arrives at the cabin.
After his men are defeated, Axminister has a rifle but climbs up onto a porch and jumps on MacGyver. Then he knocks MacGyver down from surprise. Then he unslings the rifle from his back. Finally he prepares to shoot MacGyver. Fortunately for MacGyver, Axminister forgets that he can shoot from ambush.
Another episode early in the series where MacGyver's complete aversion to guns isn't established: in the opening gambit he casually threatens two enemy agents with their own gun.
When MacGyver is cutting the tree branch, he's sitting on the branch cutting with one hand. In the next shot, he's standing behind the branch using both hands.
In syndication, the phone number Harry gives MacGyver is cut short by two numbers. On the DVD, the phone number is intact.
MacGyver's watch vanishes in one shot when he makes the stairway trap.
When MacGyver and Bill are driving the truck to the abandoned strip mine to look for dynamite, Mac is wearing sunglasses. Then suddenly, in close-up shots, the sunglasses are gone. As the truck arrives at the mine and Mac gets out, he suddenly has the sunglasses back on again.
In the scene where MacGyver and Bill are entering the shack to get the dynamite boxes, right after Bill steps off the board onto the shack's floor, there's a shot of him walking towards the dynamite boxes. The gloved hand of one of the production crew clearly comes into the right side of the shot to steady a dynamite box.
MacGyver's hands are shown to be dirty in long shots, but clean in close-ups, when he works on the truck engine.
The bit where MacGyver fixes the fuse box by wrapping the burnt-out fuse with a chewing gum wrapper does actually work as confirmed by Mythbusters.
When MacGyver and Kelly are locked in the freezer, Mac pushes a chunk of meat hanging up over to the wall – and one of the freezer pipes on the wall bends, revealing it not to be made of solid piping as it would be in a freezer.
When MacGyver is in the diner his shirt is dark green with a Chinese collar. Then he runs outside and his shirt is light gray with a normal collar.