Continuity mistake: Near the beginning, when Banner arrives at the lab with his helmet on, he removes the helmet when he sees Betty. A close-up of his face is shown and his hair is messy with part of his fringe on his forehead. Betty is shown quickly, then the same shot of Banner is shown again, but this time his hair is perfect.
Continuity mistake: When Bruce first turns into the Hulk, his wallet is seen coming out of his back pocket. When it lands on the floor it is in front of him.
Continuity mistake: The hole in the car windshield changes size from when the Hulk throws the dog through it to when it's shown the next morning.
Continuity mistake: The breast pockets on Betty Ross's denim jacket switch from buttoned to unbuttoned between shots when she is confronted by David Banner in her house at night, and again, later, when she approaches the Hulk in downtown San Francisco.
Continuity mistake: Near the beginning, when the other scientist accidentally trips the gamma machine on, Bruce helps to get the guy's gas mask on. In one shot, when Bruce throws the scientist to the ground, he is holding onto the gas mask with his right hand, then in the following face shot he is holding it with his left. (00:28:30)
Continuity mistake: When the Hulk is standing in the street, we see him standing in the fountaining water from the smashed hydrant but his hair never gets more than damp.
Continuity mistake: When Bruce first arrives at the lab in the beginning of the movie, Betty tells them that they have to present to the review board on Tuesday. After the experiment where the frog explodes Bruce asks Betty what should they present for Monday.
Continuity mistake: When the dad of the hulk comes to see his son for the "deal" he made to turn himself in to the military. You can see the type of handcuff the dads wearing changes kind two or three times in the scene.
Continuity mistake: In the scene just after the Hulk has destroyed the tanks in the desert, the camera cuts to the genera. In the first shot we see him touch the side of his head with his hand, then in the following shot his hand his on his forehead. (01:35:55)
Continuity mistake: When Bruce and Betty are in the cabin, Betty gives Bruce breakfast, and in one shot we see Bruce look at Betty, then a shot from the back shows he is looking down at the plate, then a face shot shows him looking up and at Betty again. (01:06:20)
Continuity mistake: In the middle of the film when Bruce is being taken down into the underground facility in the desert, we see guards standing around his container where he is sleeping. Look at the front, and there is a guard in front of the container with his left arm resting on it. Then it cuts to another shot, this guy is no longer in front of the container nor has his arm on it, this happens between shots. (Zoom in is required). (01:10:15)
Continuity mistake: Near the end of the film when the Hulk gets up on the cliff side to look at the choppers hovering by him, if you look where he is standing there is a small round rock behind him in this shot, but in all other shots that rock has vanished. (01:38:45)
Continuity mistake: Near the middle when Bruce and Betty have lunch, she says "were you at the lab?" Bruce isn't looking at Betty, he just shakes his head. In the following shot, his head is slightly turned and he is now looking at Betty. (00:44:50)
Continuity mistake: When Bruce and Betty are in the middle of the desert, Betty walks to the door where Bruce's parents were arguing, he walks to the door and opens it. He looks in but Betty is still looking at Bruce in this shot, yet in the following shot she is looking in the room. (01:19:20)
Continuity mistake: In the middle of the film when Bruce is in the cabin with Betty, just after he discovers a noise outside and gets shot by a tranquiliser, if you watch closely the tranquiliser is at the side of the leg, then in the following shot when we get another view of it from the floor it is at the front of the leg. (01:07:55)
Continuity mistake: When the Hulk breaks out of the government lab, he pushes up a round staircase and a soldier jumps behind it. He is then seen right in front of it when the camera angle changes. (01:34:50)
Continuity mistake: When Talbot calls out to Betty as she walks in the entrance to her building, in the background a cyclist gets on his bike and puts both feet on the pedals then starts to ride off. When it cuts to a view of Talbot, the cyclist still has his left foot on the ground and isn't moving. (00:16:40)
Continuity mistake: When Talbot goes to visit Bruce in his holding cell in the underground base in the desert, Talbot pokes him with a cattle prod of some sort. In this shot the screen splits into two. Bruce puts his hands up in the air when he gets zapped, but the other view on the screen shows that he still has his hands by his side. (01:22:05)
Continuity mistake: At the start of the film when his foster mother comes in to wake Bruce up, her hand on his head changes slightly between shots. (00:09:50)
Continuity mistake: When Betty is talking to Bruce about accepting their breakup, the camera from the front shows her looking right at him, but the camera from the back shows her looking down.
Answer: That is an altered version of Eric Bana's voice.