Visible crew/equipment: When Commodus says "The greatness of Rome. and what is that?", as Lucilla answers "It's an idea", it cuts to her walking. As she walks, look behind Commodus' throne above the arm rest, you should be able to see a yellow cord hidden behind a monument. (01:01:00)
Continuity mistake: When Commodus goes to see his father thinking his father would pass his powers onto him, if you look closely when he enters, there's a white sheet blowing rather vigorously in front of the camera. When it cuts to a shot of Commodus, the sheet now is hardly blowing at all. (00:30:35)
Continuity mistake: Watch as the Germanian leader gets killed. A soldier charges and stabs him on his left side. When it cuts the soldier charges and stabs him again. (00:03:35)
Continuity mistake: When we get to the comedy play fight between Maximus and Commodus, we look at the front of the stage and we see the actor playing Maximus is standing in the middle of the stage and the one playing Commodus on the right side. When we get a view from back of the stage 'Maximus' is standing on the left side of the stage and 'Commodus' in the middle. They have suddenly switched sides. (01:49:55)
Continuity mistake: In the final fight scene between Commodus and Maximus when Commodus loses his sword and Maximus drops his, we see Lucilla stand up but when it goes back to Maximus she is sitting back down, this happens a lot during the close-ups in this scene. (02:15:55)
Revealing mistake: When the firesquad has executed the two prisoners it cuts to a closeup of Lucilla. Later when it's time for Maximus to fight Commodus the exact closeup shot of Lucilla is being used over again. (Extended version only). (01:47:15 - 02:29:10)
Visible crew/equipment: In the scene on the DVD where Maximus' son is lunging his horse, just before he gets killed, the camera pans to show a view of the house in the background. On the right side of the house you can see two aerial power cables between the trees. You need a good resolution screen to pick it out: it's visible on my computer monitor but not on my television. (00:41:10)
Visible crew/equipment: After Maximus defeats Tigris of Gaul, there are Praetorians shown coming out of a gate on the left-hand side into the arena. In the next shot, you can see an open gate at the far end of the arena and you can see some kind of golf cart-like vehicle driving by on the outside of the Colosseum. It is very a motorized vehicle because there is no horse and it moves too smoothly. (01:43:55)
Continuity mistake: When the two guys in white are having a drink outside of Rome, the guy with the white beard looks outside, and he has his hand on his chin, yet in the following shot it's nowhere near his chin. (01:02:30)
Visible crew/equipment: During the Germanian battle, when Maximus falls off his horse you can see the ramp, on which the fake horse (yes it's fake, as shown in Special Features in the Extended 3 Disc Edition), is being pushed forward on and finally ejected off. (00:10:00)
Continuity mistake: In the wagon, when Commodus gets up and sits down beside Lucilla, the sunlight coming over his shoulder changes between the shots. (00:13:00)
Audio problem: When Proximo has lined up his slaves and says "And when you die, and die you shall. Your transition shall be to the sound of..." then he starts clapping. We hear the clapping and it cuts to Proximo clapping once then stops, but we can still hear one extra clap. (00:48:55)
Continuity mistake: When Commodus is holding Aurelius and says "Father.", he is holding Aurelius by the top of his head. When it cuts to a close-up of Aurelius looking up at Commodus, right before Commodus kills him, we see Commodus holding his chin instead of his head. (00:33:55)
Continuity mistake: When Lucilla is making tonic for Commodus there is a close-up of her hand mixing the tonic. We can see on the table there is nothing near the glass except for a purple bottle which is probably 5 centimeters from the glass. When it cuts and she puts away the spoon she tips something over on the table right next to the glass. However it can't be the purple bottle because it would have to be closer to the glass in order for Lucilla to hit it. (01:12:55)
Continuity mistake: Right before the attack on the Germanians when Maximus gets to his soldiers and shouts "Fratres.", you can see two soldiers walking right behind him. When it cuts to the soldiers shouting "Maximus.", the two soldiers behind him has suddenly disappeared. (00:06:15)
Revealing mistake: During the first gladiator battle there is a shot of Maximus stabbing another gladiator. When it cuts from behind that gladiator it is obvious that the sword is resting in his armpit before Maximus pulls it out. This happens a few shots after Hagen chops off his fellow gladiator's hand. (00:54:45)
Continuity mistake: When the chariot crashes through the gate we see the gates get busted in an exploding inferno. But when it cuts, the gates are intact again. (01:22:55)
Continuity mistake: When the chariot runs in through the gate we see the gate slightly open. When it cuts to the chariots hitting the chain and tipping over the gate is suddenly wide open. It could not have opened that fast. (01:22:55)
Continuity mistake: In the scene where Hagen is faking a choke you see Juba holding his bowl of food with both hands. When it cuts back he is holding it in his left hand only. (01:36:35)
Revealing mistake: During the first battle the Romans had with the Germans, they show a scene in slow motion with very emotive music that shows the massacre in the forest. Look closely at all the Romans and you will see one fall to the ground, then, as if it was a rewind, come back up again - and then fall again.
Chosen answer: No, they are full brother and sister. They both had the same mother and father. Incest was not exactly normal at that time, but it stretches back within the imperial families as far as Caligula and possibly earlier. There is no evidence to suggest that the real Commodus was attracted to his sister, it was probably just included in the film in order to make the character seem more disturbed, and also as another reason why he would be Maximus' enemy (Maximus and Lucilla were, after all, once lovers).
The Doctor