Factual error: In the pre-credit sequence with Bond and Blofeld, the helicopter makes a steep dive. However, the sound it makes is for a fixed-wing airplane, similar to dive bombers in WW2. Helicopters make no such sound.
Factual error: When Bond fights with Xenia in the sauna, she wraps her legs around his torso. He tries and fails to get them released, but he does create enough space between her legs which would, realistically, release the pressure on his body. (01:03:00)
Factual error: The second blackmail message from SPECTRE tells the British that they must drop the ransom diamonds in a container "off the coast of Burma, in the Mergui archipelago, latitude 20 degrees north, longitude 60 degrees east." Unfortunately, 20 N, 60 E is nowhere near Burma. It's right off the coast of Oman in the Arabian peninsula, all the way on the other side of India from Burma. The actual coordinates for the Mergui archipelago are approximately 13 N 97 E. I guess there wasn't a map handy....
Factual error: When Bond crashes the snowmobile he ends up in a ditch to escape - he uses the front ski, but when he knocks the two soldiers over he is skiing uphill - no way to manage this from a standing start in a ditch. (00:03:07)
Factual error: Of all the characters, major and minor, who ever speak German in Switzerland, not one speaks Swiss German. The accents are very different (Swiss German can be almost incomprehensible to speakers of High German), and there's also different vocabulary. While some of the characters might just be non-Swiss speakers of German, at least the underlings at Piz Gloria should be speaking Schwyzerdeutsch.
Factual error: In the scene where James Bond is being given his "gadgets", Q points out that his rifle is an "AR-7 in .25 caliber". The AR-7 is a real rifle, but is only available in .22 Long Rifle caliber. Due to numerous design features, especially the screw-off barrel, it can't be made to fire a .25 caliber cartridge of any type. (00:22:05)
Factual error: During Bond's fight in the stairwell at the lab/missile site, several soldiers use RGD-5 hand grenades against him. One explodes next to him while between a steel door and concrete stair. The RGD-5 is lethal at 3 meters and causes injury at 25 meters. Even if shielded, Bond would be severely injured by the blast damage.