When Mac and Natalia are escaping the cave on the sled with the gold bars, as the sled jumps from the cave it starts tilting backwards past a 45 degree angle and it would seem the sled would land on its back, in the process crushing them with the gold. However, the camera angle changes and it shows the sled landing almost level.
The C-47 aircraft in the episode had a "normal" maximum load of 6,000 pounds with an "emergency maximum load" of 7,000 pounds. The plane was transporting $100 million in gold bars. Even using $400/ounce, more than the 1989 maximum price, the gold would have weighed over 15,000 pounds. If it was the WW II value, the gold weight would have been over 190,000 pounds.
The airman in 1944 would never have been able to give such an exact location (62°41'19"N, 164°19'38"W) with the technology they had then. And MacGyver would have had no way of actually finding that exact location using the technology available in 1989.
That weight of all of the gold bars would weigh over six tons. Not only would the sled have never held that much weight, they would have never been able to get it moving.
When Macgyver finds the box with the Russian label he asks Natalia Velskaja to read it and she says the box is only to be opened by American military personnel. While it makes sense the label would be in Russian for the Russian crewman, it doesn't make sense that there is no equivalent label in English for the American to read.
The surviving US service member of the plane crash that went down in 1944 is still in the military in 1989 (when this episode is set/filmed). That means he would have served for a minimum of 45 years. You can not serve that long per military regulations.
The story takes place in the Arctic. But the lat/long coordinates on the back of the gold bar (62°41'19"N, 164°19'38"W) are for a location in southwest Alaska, which would not be reachable by land. Later when West is locating these coordinates on his topographical map, we can see the Copper King Glacier on the map (near the lower right corner). The Copper King Glacier (56°36'0"N, 130°37'0"W) is in northern British Columbia.
At the beginning when the plane is shown crashing there are very high mountains, like those found in the Alps. There are no such mountains in the Arctic Circle region of North America.