Revealing mistake: When Bond pushes Kriegler through a window, we can see in the shot of Kriegler falling that he is just a dummy.
Revealing mistake: In the sleigh scene in Cortina, the closeups are recorded in a studio. The view of the background fits very poorly with the surroundings in the intermittent wide shots, which shows buildings close by, while the background just before showed a wide valley view.
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.
Revealing mistake: When Locque kills Countess Lisl by running her over in his dune buggy, look in the cockpit and you can see that the driver is not Michael Gothard but his stunt double.
Revealing mistake: When Bond enters Q branch, he is met by a technician with a false broken right arm. After saying "Coming along very nicely sir" the arm then swings to the technicians' right breaking the head of the dummy. This then reveals the arm of the technician, who then holds his hands suggesting the false arm is a 'Spy Gadget'. You can see that the revealed hand is not that of the actor but of someone stood behind the set wall. The actor has used his real arm to carry out the effect, and then clasped the hand of the extra person. This is supported by the fact the arm movement can be seen through the shirt, the skin complexion of the hand is completely different to the actor, the arm looks like he is being hugged, when he puts his hands together it is not natural, and as they move away he moves his right shoulder up and the 'third' arm remains in place.
Revealing mistake: When Apostis kicks Bond in the face when he reaches the top of the cliff, you can see it is not Roger Moore but his stunt double.
Revealing mistake: Kristatos wants to run over Bond and Melina by boat, after he took the Atac. Bond and the girl swim to the sea floor, waiting till Kristatos is gone. You can see the (shadow of) the anchor hanging on the left side of the ship. But in the previous scene, you will notice the anchor is in the middle, on deck! And second: these kind of (speed)boats do not have an anchor attached below the water line, because it will reduce the speed. Conclusion: the underwater scene is fake.
Chosen answer: Whether he talked to her or not, Bibi would have inside information simply by being around him so much. She would have overheard things that a background check wouldn't reveal, like planned criminal activity.