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.
Audio problem: At night when MacGyver and Jack are sneaking past the guards behind a mule, we see about 8 to 10 light bulbs hanging overhead. MacGyver later pulls the cord down and all the lights begin to pop. There are about 16 pops, many more than there were bulbs on the cord. (00:24:50)