Continuity mistake: When Hinx appears in the dining car on the train, the rest of the passengers in that car immediately disappear. Also the barman when they enter that part of the train and the kitchen staff too.
Continuity mistake: At the start of the car/plane chase the road is completely wet. After the cars exit the tunnel the road is bone dry. When the cars turn off the road into the trees the road is completely wet again.
Continuity mistake: In the tunnel where Bond's Jaguar is wrecked by a truck it shows Moneypenny, Q and Tanner getting shot at, which shatters the right rear window where Q is sitting. Shortly after, they meet up with M to race away, and only a bullet hole is seen in the same right rear window of the vehicle. (02:02:20 - 02:02:50)multicomm
Continuity mistake: When Hinx shoots at the plane he only shoots 3 times but the damage on the side shows 5 shots were fired. He's using a double-barrelled pistol which fires two shots at a time, so there should have been 6 holes - it's not accurate enough for two bullets to go through one hole.