Other mistake: When Indy and Marion are sealed in the well of souls, they are completely cut off from the outside world. As such, other than the torches, it should be pitch black, but it is surprisingly well lit in there.
Continuity mistake: After the plane takes off in the beginning, Indy sees the snake. His hands are grabbing at it, but a second later his hands are on the rim of his cockpit.
Continuity mistake: When Indy is driving the truck with the ark, a German tries to get in on the right side. Indy kicks the door open twice, and after the second time the top hinge of the door gives easily. The guy is half way dragging on the ground, holding onto the now askew door. Then in the next closeup, the door is hung correctly with the guy on it, and Indy kicks it again. The guy goes dragging again, and then he and the door fall off.
Continuity mistake: There is a shot during the truck chase scene where a Nazi falls out from the back of the truck and goes through the windshield of the car behind it. During the shot from inside the truck, we see two Nazis to the left. The one closer to the camera pushes the other one down. However, in the very next shot, we see that pushed-down Nazi immediately sitting up straight.
Continuity mistake: From the outside, the sides of the hole to access the map room are in shadows, from the angle inside they are sunny.
Continuity mistake: During the truck chase scene, the radiator bars Indy hangs onto keep swapping back and forth from bent outwards to slightly bent with no continuity at all.
Continuity mistake: In the submarine dock of Geheimhaven, Captain Mohler is a man with dark hair in his mid or late thirties. But during the procession, he seems to be much older, with grey hair.
Factual error: There's absolutely no way Sallah and Indy would be able to lift that 'lid' (for lack of a better word) off the ark. That thing is solid rock and would weigh close to a metric ton - and none of them look like professional deadlifters to me.
Factual error: When Indy is attempting to steal the Ark when driving the truck, one of the soldiers shoots him in the arm. Then another German punches him repeatedly in the same arm, causing Indy great pain and injury. After suffering a wound like that there's no way he'd be able to move that arm, let alone raise it above his head. But the next day after the boat is stopped by the sub, Indy jumps into the water and swims to the sub without any problems.
Continuity mistake: When Indy stands inside the Map Room, looking at the model of the city, the rays of the sun are to his left, and they move right and down as the sun rises. But since the entry hole is behind him, that would mean that the sun would be to the right when standing outside - but it was to his left when he entered the hole.
Continuity mistake: When the temple collapses, Indy is holding the idol with his right hand against his chest, and the left hand free and arm extended. A frame later, both arms are extended and holding the idol.
Visible crew/equipment: When Indiana frees Marion, locked in the cabin pilot of the Nazi plane just after one of the soldiers is killed by the blades, a set light is reflected on the plane's glass. (01:20:32)
Continuity mistake: When we first see Colonel Dietrich, he, Belloq and Gobler are crossing Tanis on foot. The scene cuts out when the three of them arrive next to some wagons. However, seven minutes later (in movie time) they are shown again in exactly the same position as they were in the first shot, continuing their actions. This is also seen in the two soldiers in the background on a hill and in a soldier on horseback going from left to right. Even Indy’s team is visible in the first shot, when he is supposed to be in another place only with Sallah. (00:50:09 - 00:57:00)
Continuity mistake: When the sergeant throws Indy out of the truck window, the adventurer grabs the Mercedes logo with his left hand. After two shots, he is to have let go. However, in the next shot, Indy is grabbing it again. (01:27:25)
Continuity mistake: As the Nazis are preparing to leave Tanis, a soldier fires a shot into the air, causing several Arabs to fall to the ground and land in the middle of a circle of soldiers. In the next shot, as Belloq heads for the car, all the downed Arabs, the sergeant and the circle of soldiers have disappeared, with only the soldiers who were loading the Ark onto the truck remaining. (01:26:55)
Continuity mistake: Just as Indy crashes Gobler's jeep for the second time, you can see that beside the desert road is a large forest. However, the jeep falls off a cliff that appears out of nowhere. (01:25:37)
Continuity mistake: When Indy throws Terry Leonard out of the truck, the forest they were driving through disappears. Then Indy closes the truck's door and the forest reappears. (01:24:22)
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)
Audio problem: When the camera focuses on Belloq as he looks into the Ark, Toht's screams are inaudible, despite being right next to the Frenchman. Only when the shot changes to show Toht his screams can be heard.
Continuity mistake: Dietrich asks, "If we refuse?" Next to him stand four soldiers in a row, looking at Indy. In the next shot, the soldier who was holding a rifle is gone, and the two with machine guns are now giving their backs to Dietrich. (01:42:52)
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.