Factual error: A 250-year-old sea chest recovered from the ocean floor is opened, and all its paper items are perfectly dry: the log book can be opened and read, and the letters can easily be unrolled. Highly unlikely. The chest's wood and pitch would deteriorate (salt water is extremely corrosive), and the paper should be damp and crumbly, at the very least. Even more likely, it would have become a lump of unreadable sludge.
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.
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: Perhaps s02e13, "Soft Touch." Penny Parker (player by Teri Hatcher, who would have been 22 at the time) crashes at Mac's place. She performs singing telegrams and takes Mac's Jeep to her next job, but goes to the wrong house and sees 3 men torturing someone. She drives away and the men chase her, noting the license plate of the Jeep. Penny convinces Mac to help, but she's unable to remember which house it is. Later, the men find out where Mac lives and kidnap Penny and a Serbian (a guy from the beginning of the episode), Mac follows and he reveals the bad guys' plot to kill someone at city hall involved in a drug case. The three rush over to city hall and prevent a bomb from going off and the bad guys are captured.
Bishop73