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: 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)
Trivia: In the Well of Souls, you can see hieroglyphics of C3PO and R2D2 on the wall.
Continuity mistake: When Indy goes to save Marion in the tent he removes the handkerchief gag. But when he decides to leave her there, he puts the gag back on and some of her hair gets caught underneath the gag on one close up shot from the left. But when the camera goes to the back of Indy, her hair is no longer caught underneath the gag. (00:56:00)
Continuity mistake: Near the beginning of the movie where Indiana is running away from the tribe of South American Indians after Belloq robs Indiana of the gold statue, in one shot you can see that the Indians are only a few meters behind Indiana, but in the next shot, they are at least 50 meters behind. (00:11:20)
Visible crew/equipment: As soon as Marion gets locked in the cockpit of the Nazi plane, you can see a crew, a blue van, a ladder, and a crew member with a white sleeveless shirt and a big brimmed hat, all in the reflection of the glass. (01:18:20)
Continuity mistake: Before the shoot-out in Marion's bar, before the Nazis enter and ask her for the amulet, she's sitting alone at the table. She pulls the amulet out of her shirt, the chain still around her neck, and stares at it in the candlelight. The next moment the chain is not around her neck and she hangs the necklace onto the table centrepiece. (00:28:20)
Revealing mistake: When Indy fights the driver of the Nazi truck, he gets thrown through the windshield, and eventually ends up underneath the truck. When he is climbing underneath the truck, heading towards the back of it, you can see the trench that was dug down the middle of the road to provide the stuntman (this being one of the few stunts that Ford didn't do himself) with the extra room needed to do this feat. (This is backed up by DVD commentary. The director stated that the truck was too low to the ground so they had to dig the trench in order for there to be enough room for the stuntman). (01:27:50)
Continuity mistake: When Indy is distracted by the young girl and her eyelid message, the girl changes from a window seat to another row when the bell rings to end class.
Continuity mistake: In the Himalayan bar scene when the sherpas leave, Marion starts to pick up the shot glasses and puts them on a tray - there's a large group left at one end of the table, one in the middle, and two by a bowl at the other end. When she returns for the rest, the two by the bowl have vanished. (00:26:20)
Continuity mistake: When Belloq is talking to Indy and Marion in the Well of Souls, he's shown holding his hat with his right hand. But in the only over-the-shoulder shot (looking into the Well of Souls) the hat is laying on the ground and Belloq tosses a stone down with his right hand. Then the hat is back. (01:10:35)
Visible crew/equipment: When Indy and Sallah are deciphering the head piece there is a shot over Indy's shoulder. As he turns you can see the reflection of a fluorescent light in his glasses. (00:48:40)
Continuity mistake: The stone block Indy pushes out to create an opening which allows him and Marion to escape the Well Of Souls apparently rolls down the hill outside. We see it, in a following scene, laying about 15 feet away from the Well. But when Indy is fighting the big German guard near the airplane, one scene clearly shows the Well in the background and the dislodged stone is now laying on the hill only a few feet from the opening. (01:15:45 - 01:18:10)
Continuity mistake: When the government comes to see Indy at the University he is teaching, they enter the large room, I think it's a gymnasium. He puts the huge book on the table and one of the buckles comes undone. But when he goes to open the book to show the g-men a picture of the Ark he undoes both buckles. (00:15:30 - 00:19:30)
Continuity mistake: When Indy is being lowered into the map room, the exterior shot of the opening does not match the interior. From the outside, the wall around the opening is a lot thicker. The angle is also different. (00:50:55)
Continuity mistake: When Indy is trying to stop the truck that is supposedly carrying Marion in a basket, Indy shoots the driver as the truck heads towards a "dead end". The driver's foot hits the accelerator and the next shot opens up to a big open space where the truck tips over and explodes. The "dead end" has disappeared. (00:40:10)
Revealing mistake: Just before Belloq says "beautiful", look carefully at the woman's ghost in the center of the screen. You can see one of the wires on her back that makes the stunt woman fly, a black line above her left shoulder.
Continuity mistake: Just after Indiana (barely) escapes the tumbling boulder at the beginning of the movie, he leaps through a veil of spider webs, only to be held up by the native hunters and Belloq, who takes the idol from Indiana. Watch carefully - there is a thick strand of webs attached to the idol as Indy hands it to Belloq, but they disappear in the next shot as Belloq hefts the idol and holds it up in the air.
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.