Deliberate mistake: The famous car chase ends with Bond's car tipping up on its right wheels to fit through a pedestrian path. However, when it emerges the other side, it's tipped on its left wheels. When the car enters the alley, this was filmed in a studio. When the car exits the alley, this was filmed in Vegas. The first few times the exit was filmed, the car emerged on the correct wheels, but the shots were unusable because of the crowds in the background watching the filming. This shot was temporarily abandoned and eventually re-filmed with a different stunt driver who famously performed the stunt on the wrong wheels. Realising this, the producers filmed a somewhat clunky insert shot featuring a close-up of Sean Connery and Jill St John, which shows the car tip back onto four wheels and then up onto the opposite two wheels, even though the alleyway would be too narrow to manage this.
Revealing mistake: When the Hovercraft pulls away, you can see a passenger look out his window and wave directly at the camera. (00:16:00)
Continuity mistake: During the car chase scene through Las Vegas, you can see the crowds lining the streets to watch the filming, yet in some of the street scenes there are no crowds.
Revealing mistake: Many times throughout the car chase in Las Vegas between Bond and the cops, you can see skid marks where they tried earlier stunts with the cars on those points on the road. The most obvious is when Bond pulls away from the Sheriff after he approaches the car.
Continuity mistake: When Mr. Kidd tries to kill James with the flaming shish-kabobs he is wearing gloves, which weren't there immediatly before.
Visible crew/equipment: When Bond and Tiffany speed away from the Tectronics facility, three of the security guards are at their inoperative vehicle, and there's a reflection of film crew on the surface of the vehicle.
Visible crew/equipment: At the Tectronics facility, Bond swipes a quad bike from one of the security guards chasing him. When he reaches Tiffany at the perimeter gate, just as Bond says, "If you see a mad professor in a minibus, just smile," we can see the reflection of the boom pole/mic on the car's windshield, as well as the hood. (01:03:05)
Continuity mistake: When Bond raises the man in the mud's head, the mud is smooth. From an immediate new angle, it's rugged.
Continuity mistake: When the cops chase Bond in Las Vegas, they all drive by many cars. However, in a close-up inside the police car, one can see an empty road behind.
Revealing mistake: When the guy in the tub gets covered in mud, his swimming cap to protect his head protrudes around the ears. After Bond sprays him with water, the cap is gone.
Answer: If you mean by hiding - why is he never seen normally - then it's because he is a recluse and doesn't like to be seen in public (like Howard Hughes was). If you mean by hiding - why was he not seen during the movie - then it's because he was being held captive by Blofeld and his minions. Spectre didn't want him out and about ruining their plans.
Zwn Annwn