Continuity mistake: When the Neptune is hauled aboard and Kristatos begins talking, you can see his yacht in the background moving slowly. When Apostis takes the ATAC system away from Bond and Melina, the yacht is now much closer, at apparently the same speed.
Continuity mistake: When Kristatos brings the Neptune sub up, Melina gets out, and stops at the bottom of the ladder, still holding the handrails. In the very next shot, she is standing off the ladder and closer to Bond.
Continuity mistake: When the two black cars leave Gonzales' estate to pursue Bond and Melina, look at the first car and you can see the driver is not the same one who appears later on in the chase.
Revealing mistake: When Bond pushes Kriegler through a window, we can see in the shot of Kriegler falling that he is just a dummy.
Continuity mistake: Bond fixes the end of his rope with a spring-loaded camming device (which is unsuitable for lose, porous rock by the way). When Apostis tries to dislodge him, the end loop of the rope is fixed to a piton - it has to be, because SLCDs literally cannot be knocked out of the rock.
Revealing mistake: As Bond prepares to drop Blofeld into the smoke stack, you can see that the cervical collar isn't put on correctly, the actor can still move his head. The intention of a cervical collar is to take all strain off the spine and neck muscles and prevent any movement that could cause damage to the spinal cord. To work, a stiff neck must be fixed so the neck is completely immobilized and slightly extended. However, wearing a cervical collar is very uncomfortable to the wearer, so they probably used a slightly lower one and didn't fully tighten it.
Revealing mistake: When "Mac" is told by the captain of St. George's to destruct the ATAC system, an explosion occurs and he gets thrown to the ground. When this happens, you can see that the man playing Mac is his stunt double.
Character mistake: When Bond contacts the Chief of Staff after identifying Locque on the Identigraph, Bond reads his bibliography to him. The first appearance of the word bibliography is misspelled "BIBLOGRAPHY", whereas the second appearance near the bottom of the screen is spelled correctly.