Visible crew/equipment: As they drive the car out of the plane with a parachute you can also see someone else (another camera man probably) jump out right behind the car in the same shot. (00:45:30 - 00:46:05)
A Prisoner of Conscience - S1-E21
Continuity mistake: When Pete steals the drugs, he puts them in his pocket and drops a bag right near the door, but when the doctor comes in and finds it it's much farther away from the door than where he dropped it.
The Prodigal - S1-E9
Continuity mistake: When the car breaks down and MacGyver backs up the tow truck he hits the Fed's car, but in the next scene after he gets out of the truck it is feet away, he never moved the truck.
Factual error: Some factual errors regarding Basques: 1) Basques have not been fighting for ages against France and Spain, and they do not kidnap US citizens. 2) Basques do not look, in any way, like South Americans. 3) Violent Basques are not guys "up on a mountain" with old rifles, but terrorists with modern weapons.
Flame's End - S1-E13
Visible crew/equipment: As Amy and MacGyver are chased around a nuclear reactor just before the bad guy gets nuclear steam on him, you can see a pair of legs in a top row window around where they are walking. Remember the nuclear reactor was hot with radiation so no-one would be wandering around.
The Gauntlet - S1-E4
Visible crew/equipment: While Macgyver is running into the desert, a camera is visible in the far right of the screen. (00:05:07)
Flame's End - S1-E13
Other mistake: MacGyver and Amy get locked up in the nuclear disposal chamber with the sludge coming for them. Amy says "before it reaches this room it will get too hot for us to breathe", but just as MacGyver closes the door after managing to get it open, the sludge pours in. At this point they're breathing just fine and not sweating at all.
Character mistake: At the border crossing during the car chase there is a mistyped sign below the window reading "Bunesrepublik Deutschland". it should be "Bundesrepublik Deutschland" (00:07:45)
Continuity mistake: When MacGyver drives the forklift into the car one of the forks goes through the windshield. When the shot changes it is now out of the window. You can see the broken windshield where it had gone through.
Other mistake: Spencer somehow manages to get shot even though the bad guy never points his gun at her.
Visible crew/equipment: When the pursuing police car exits the sewer, two mannequins can be seen in the driver and passenger seats. (00:42:35)
Factual error: MacGyver and Victoria go back to the location of the science event to think about the incident. MacGyver's friend, Bannister, suffers from a heart attack. MacGyver cuts a microphone cable and binds the cords to a metallic candlestick. MacGyver uses his creation as a some sort of defibrillator. Of course it works and MacGyver saves his friend. The maximum power in the wire is 11-48v DC with the maximum current of 10MA - not enough for giving huge electric shocks.
Answer: Late one night, Geoffrey used a covert listening device to overhear David explaining his barricade device to Janet which is how he figured it out.
How do we know Geoffrey really did use a covert listening device? They didn't mention him using one.
There was a scene of him using it when David told Janet about his barricade.