When Batman, Batgirl, and Robin leave Poison Ivy's Turkish Bath hideout and go after Mr. Freeze, their outfits all change. Batman gets a new bodysuit with a bat logo that takes up the entire chest, Robin gets a suit with a white bird insignia (as opposed to the red on his other one), and Batgirl acquires a Batman-style mask. With time being of the essence it's not likely they would have gone back to the Batcave to change outfits.
Before and during the final confrontation at Gotham Observatory, Robin is wearing a batsuit with a silver "Robin" logo across it. But when they return to Wayne Mansion and Batman inserts the blue phials into Alfred's drip, Robin's wearing his old batsuit with the red 'Robin' logo on it.
When Bane breaks into the Turkish bath he is wearing a trench coat. When he gets inside the trench coat is gone.
When Poison Ivy arrives at the Gotham Charity Flower Ball, the length of her hair changes throughout the scene.
In the final battle when Bane attacks Robin and Batgirl, he grabs both by the throat and pulls them backwards away from the ledge, in the very next shot however he is pushing them forwards into a wall.
When Batman free falls on the telescope, along with the two scientists, they dive for approximately 30 seconds, which means that the observatory is located at about 4 kilometers (5,000 yards or 2.7 miles) above the ground and that Batman wears a 4 km long grappling hook/bat-rope.
In Mr. Freeze's lair at no point do you see the henchman's breath. If it was really freezing cold you would see their breath. The air in human lungs is almost completely saturated with water vapor (water in gas form) and is the same temperature as human bodies (98.6oF). Cold air cannot hold as much moisture as warm air. So when one exhales a warm, saturated breath on a cold day the cold air rapidly lowers the temperature of human breath, whereupon the combination briefly reaches dew point. At dew point, air can no longer hold water vapor; when air is cooled beyond dew point water vapor turns to liquid form, the physical process known as condensation. It is this liquid form of your breath - minuscule droplets of water - that creates the fleeting, misty cloud you see when breathing in cold weather. As a result molecules slow down and lump together. There's not an exact temperature at which condensation will occur but usually when the temperature is below 45 degrees Fahrenheit, you can usually see your breath.
Regardless of how the starlight gets to the telescope, Gotham City has way too much light pollution. The astronomer would not see stars, just a fogged image from bright lights.
In Mr. Freeze's lair in the freezing temperature his henchman are shivering in their closeups. Yet if you look closely at their faces some of them are actually sweating in their bulky costumes under the hot studio lights.
When Barbara is looking at the CD-ROM that Alfred gave her, she looks at a photo of her mother. It has nothing written on it. She then flashes back to her memory of a different copy (Alfred's), which has "Love, Peg" written on it.
Freeze says "What killed the dinosaurs? The Ice Age!" It is not known what caused the dinosaurs' extinction, but it could have been an Ice Age.
When Mr. Freeze ices a police car, you later see the car door open, and the icicles on the door sway back and forth as if made of rubber.
During the standoff between Ivy and Batgirl, Robin emerges briefly from the pool of water, before being pulled back in. This footage was obviously not filmed at the time but added later on - it's actually footage of Robin getting out of the pool once the fight is over which has been played then reversed to make it seem like a full movement.
Barbara turns to react to Bruce's line, "Oxbridge Academy, Alfred's alma mater" a split second before Bruce actually says the line.
When Batman is lifted upside down by Poison Ivy's vines, his cape is clearly attached to the sides of his legs.
When Barbara arrives at Wayne Manor, she says that she is looking for Alfred Pennyworth, then exclaims "Uncle Alfred!" in response to seeing him... about a second and a half before he actually comes around the corner.
After Poison Ivy kisses Robin, Robin reveals he had protective 'wax lips' and peels them off. Ivy could've easily pulled him forward and kissed him again (fatally poisoning him), instead of to push him into her vine-invested pond.
When Robin gets the diamond he says, "Swing!" This is supposed to be a reference to repeated catchword from Wayne's World (1992) and the earlier Wayne's World sketches on Saturday Night Live (1975). Typically accompanied by a pelvis movement, it is supposed to represent the sound of a sudden erection. The actual word is "schwing", not "swing".
One of the character errors states that in the beginning of the movie, Batman's eyes are shown as blue while putting his mask on. However, this may have actually been a shot of Chris O'Donnell who plays the character Robin.
In order to apply for a credit card you are required to provide all of your personal information such as name, address, and social security number. The bank who issued the card to Batman would easily know his true identity.
When Mr. Freeze says, "I hate uninvited guests," his lips aren't moving.
When Alfred, Barbara, Bruce and Dick are walking through the garden, Dick says, "You have secrets, Al?" but his mouth never moves.
When Mr. Freeze says, "Then it's winter forever in Gotham," his lips do not match with the words one hears.
When Batman and Robin pull grappling hooks from their utility belts, it zooms in and they are made of wobbly rubber. Whey they throw the hooks in the next frame, it makes a "clink" noise of steel hitting steel as they grab.
When Barbara is trying to guess the password, it shows the monitor as she types the full name "Wayne." It then cuts to a shot of Barbara and she can be heard typing two more letters.
At the beginning when Batman and Robin are skating in the museum it is obvious that they are wearing inline roller skates.
During the Bike Race scene, after Robin and Barbara come off their bikes and slide towards the end of the bridge you can see the rail tracks upon which the bikes and actors are being pulled along by.
When Batman, Robin, and Batgirl use the grappling hooks to pull themselves up to the Gotham Observatory, as they land inside the observatory on the lower right corner is a crew members head.
When Poison Ivy and Bane come to steal the Bat Signal it is already activated - why? There's no emergency and if there was, there would be at least one officer operating or guarding it.
Mr. Freeze and Poison Ivy do not seem very compatible as partners because he wants to freeze the world and she wants plants to roam the world. Plants do not survive in freezing temperatures.
Freeze's body needs to be kept at a low temperature, yet he smokes cigars and wears a bathrobe and slippers.
In the opening fight after Freeze blasts off into the atmosphere he is holding Batman hostage inside and as the capsule rising the inside begins to freeze which would eventually kill Batman (as altitude increases temperature decreases). However Robin is outside trying to climb in and he is perfectly fine despite being at the same altitude.
Ms. B. Haven shows no ill effects from being severely underdressed in Freeze's frozen hideout.
When in the space rocket, Mr. Freeze says "At 30,000 feet, your heart will freeze and beat no more!" Obviously, this is false as the human heart can survive that altitude without freezing and the first thing to freeze would be his limbs, not his heart.
When the Dynamic Trio is trying to unfreeze Gotham and can't wait the five hours until dawn, Robin suggests they use the satellites to reflect the sunlight "from the other side of the equator". This in and of itself wouldn't accomplish anything; the equator is a measure of latitude, while time of day (or night) is determined by longitude.
At the very beginning of the movie when Batman is getting dressed, the person who pulls on the mask has blue eyes, however, George Clooney who plays Batman in the film has brown eyes.
When we first see Dr. Pamela Isley, she says, "Drats! My experiments to mate the Dendrobium orchid and the South American rattlesnake have failed again!" The orchid shown is a Paphiopedilum (slipper) orchid, not a Dendrobium.
When Dick/Robin catches Barbara/Batgirl returning a motor bike, she throws him to the ground and he asked her if they teach her that (move) at Oxbridge. Barbara replies that she takes judo lessons because London is kinda rough. Oxbridge is an amalgamation of the two top universities in England - Oxford and Cambridge - it is used to describe a person who went to either university, so it is not an actual place. In addition, neither university is located in London.