Plot hole: At the start of the movie, a great deal is made of the boom mic that enters the shot. This is ridiculous, because Bolt's view would not be restricted to what was onscreen, he'd have a perfect view of the person holding the boom mic (as evidenced by it not being stable). There's no possibility of him not seeing the person holding the mic either. As Bolt completely and utterly believes the world he lives in, and thinks the situations he finds himself in (saving Penny) are real, someone holding a boom mic would break the illusion for him. In all instances in the movie where an outside force (i.e. a dog handler) interacts with him, Bolt never gets to see the person handling him (handler approaches from behind), the boom mic operator however is literally right in front of him.
Audio problem: (May only apply to the original VHS release.) When Scar has Zazu locked up in a cage, Zazu mentions Mufasa's name and Scar yells at him, "What did you say?" Right before Scar's actual line, whilst Zazu is talking, you hear Scar's "What did you say?" line very faintly in the background, even though Zazu has not even mentioned Mufasa yet.
Other mistake: After the great fire scene there is a raccoon that drags her baby to shore and begins cleaning it. A few seconds later the baby has jumped across to the other side of his father and siblings, but the mother does not stop licking. This error has since been fixed in newer releases.
Continuity mistake: The tiger bites the seat off the suitor's trousers, allowing the viewer to see his polka-heart boxers. When we see the tiger in the courtyard, he has a part of the same boxer shorts in his mouth. So if he bit off the seat of the trousers, shouldn't he have purple cloth in his mouth? (00:11:45)
Continuity mistake: In the 'Gaston' song sequence, near the end, Gaston is sitting in his huge antler chair with Lefou. In the wide shot, there is a bear rug behind the chair. The camera does a close up of Gaston, then in the next wide shot, the chair is on top of the bear rug. Also, after this, Gaston gets up off of the chair and in the next shot, both the chair and the rug disappear completely. (00:29:20)
Continuity mistake: In the beginning scenes, where Milo Thatch is practising his proposal, he slides over (face forward, chest against the board) a chalk drawing of a map detailing the location of Atlantis. When he realises he wiped off the drawing, and sees it on his clothes, he stands in front of the blank part of the chalkboard, "filling in" the space with the map that rubbed off on his shirt - the only problem is, that the image should have rubbed off backwards as he was facing the board when it transferred to his clothes. He could not simply stand in the place of the missing map face forward and have it read properly.
Continuity mistake: When Mrs. Otterton is in Chief Bogo's office holding her family photo with both paws, in the wideshots her purse is hanging in the crook of her left arm, but after a brief shot of Judy, when it cuts to Mrs. Otterton's closeup as she tells Bogo about her two beautiful children her purse is gone, then after another brief shot of Judy the purse is back in its place again in the wideshot.
Continuity mistake: Just before Flynn cuts off Rapunzel's hair, there is a shot from behind him and he reaches up with his right hand to push her hair behind her ear. His arm is visible up to his forearm and the shackle is nowhere in sight. However, in the next, wide shot, the shackle is suddenly up around his wrist. (01:01:20)
Other mistake: In the intro to the Pastoral Symphony, the narrator identifies the deity who cloaks the world with Night to be Morpheus, who is the Greek god of sleep and dreams. However, the character in the animation is fairly obviously female, with long hair, eye shadow, and lipstick. My theory is that the character was intended by the art team to be Nyx, the Greek goddess of Night. Night would be a more likely candidate to be making it nighttime across the world, while Morpheus would be more likely to put people to sleep or send them dreams.
Continuity mistake: When Kuzco and Yzma make a dive for the potion bottle, Yzma is turned into a cat simply by landing on the potion bottle. This suggests that a person only needs to touch the potion in order to be affected. However, when Kronk and Yzma are serving Kuzco dinner and are trying to avoid poisoning themselves, Kronk pours his potion drink on himself and is not affected.
Continuity mistake: When the butler takes the mother and kittens to be abandoned in the countryside he is on a motorcycle and sidecar combination. During the trip the sidecar changes from one side of the bike to the other and back again. Also, when the sidecar separates from the motorcycle when the dogs are chasing Edgar, the wheel on the sidecar switches sides regularly as well.
Deliberate mistake: When Tarzan fights with the leopard, it scratches his chest. However after they fall into the pit and Tarzan comes out carrying the dead leopard, the scratches on his chest have amazingly healed. [It is a long-standing Disney tradition that no evidence of violence is shown on screen. Still a mistake, but there's why].
Continuity mistake: During the archery constest, in one scene Prince John has a ring on his right paw with no jewel, then all of a sudden the jewel appears. a few scenes later he has three rings on that paw, and later he has no rings at all.