Continuity mistake: When Indy abruptly brakes the truck and the Ark box slides backwards, the poles on either side of the box disappear for the rest of the chase.
Continuity mistake: After the kliegs and generator explode, there is a shot of Belloq and Toht on the altar. Belloq has the ivory rod in a vertical position. In the next shot, the rod is horizontal.
Continuity mistake: When the two soldiers place the Ark on the altar, they move to the walls of the canyon, and Toht stands next to Belloq. A few shots later, the soldiers are next to the Ark's poles (where they will be in the next shot), and Toht seems to be very huge. (01:44:39)
Visible crew/equipment: Just before the shooting starts at The Raven, you can see that Otto's shadow movements do not match the German's movements. Also, when Marion fights with Toht, behind her you can see the shadow of a man with short hair and no hat moving to the left (Indy still has his hat on during this scene).
Continuity mistake: Dietrich and Gobler walk forward to stand next to Belloq while he's saying, "Once again, Jones..." In the next shot, Gobler has disappeared (this can be spotted by the distance between Belloq and Gobler's foot in the first shot). (01:10:57)
Continuity mistake: When Indy runs over the sergeant, the background behind the truck changes between shots, going from the desert to a mountain. (01:28:45)
Continuity mistake: When the Nazis are aboard the Bantu Wind, in the full scene of the ship deck, Toht stands behind Belloq. But, after Marion tries to hit Dietrich, the camera focuses on Belloq, then on Dietrich again. Toht is not seen anymore on the deck.
Continuity mistake: In the canyon, in the shot of Toht, just before Belloq says "Do as you will", everyone in the background (Marion and her two guards, Dietrich, some soldiers) is gone (taking as reference the giant stone behind Belloq and the characters' positions in the previous and next shots). (01:43:49)
Continuity mistake: As Gobler's jeep is returning to the road after being hit by Indy, Gobler's goggles move from his eyes to his cap between shots.
Continuity mistake: At the beginning of the Truck Chase, when Billy Horrigan starts shooting at Indy, Reg Harding's right hand goes from grabbing the front passenger seat to grabbing the metal bar of the jeep between shots. (01:23:28)
Visible crew/equipment: During Marion and Belloq's beverage contest, a round klieg lamp's blue light stands behind Belloq, which sometimes changes its intensity. Also, when Marion grabs the knife, behind her a moving light can be seen (like a helicopter's light), which disappears a few seconds later. This light also appears for a few seconds when Toht frees Marion's arm.
Continuity mistake: After the kliegs behind Dietrich, Belloq, and Toht explode, the Ark's energy begins to destroy the soldiers' guns and the kliegs next to them. In some shots, the kliegs on the altar are still working.
Continuity mistake: Just before Belloq says "It's beautiful!", there is a black machine (which is not the German camera or the generator) in the bottom middle of the screen, just below the approaching ghost. It is also visible when the Angel of Death is revealed. This machine disappears when the Ark begins to kill the soldiers.
Continuity mistake: When Dietrich and Toht look at the ghosts that pass behind them, the column of mist that is coming out of the Ark disappears.
Continuity mistake: As the sergeant climbs to the truck's roof, Belloq turns his head to watch the scene. In that shot, the staff car is passing next to a group of plants. In the next shot, almost all the plants have disappeared. (01:26:55)
Visible crew/equipment: Just as Indy and Sallah walk near the table with the soldiers eating, on the dune in the background (near the Map Room), four crew members (not wearing German uniforms or Arabian tunics, but shirts and jeans) can be seen sitting, watching the scene. (00:54:46)
Visible crew/equipment: Right when the Nazis are struck with the light, one soldier shakes wildly and one can see the cable coming out of his trousers and stretching off-screen to the right. (01:47:30)
Continuity mistake: When Indiana is confronted by the Cairo swordsman, he already has his left shoulder pointing towards his opponent in the shot where the crowd scatters. But in the following shot, where the swordsman is first seen, Indiana has his right shoulder pointing forward and is just turning around to his left side. (00:40:14)
Continuity mistake: The amount of moss behind the idol increases between shots.
Answer: The scene you describe was indeed filmed. It was cut out of the US release of the film although I cannot speak for the Australian version. The scene also appears in the Marvel Comics adaptation. http://www.theraider.net/films/raiders/deleted_scenes.php has a list of this and the other deleted scenes.
Phil C.