Colin Farrell stated that he went to Starbucks to try out his prosthetics and makeup for the Penguin for the first time. Nobody recognized him, but he got a couple of stares from people.

Robert Pattinson revealed while auditioning for the role, he sneakily took a selfie in the batsuit as a memento "just in case it didn't work out."

Robert Pattinson's audition/screentest took place while he was in rehearsals for shooting Tenet (2020) in Los Angeles in May 2019. Pattinson had to lie to Sir Christopher Nolan about it, but Nolan, who was no stranger to Batman and Warner Bros., immediately figured it out. Pattinson: "I said I had a family emergency. And as soon as I said it, he goes: 'You're doing the Batman audition, aren't you?'" When Pattinson was told that he won the role of Batman a day before principal photography for Tenet began, he was surprised that Nolan also knew and congratulated him, although Pattinson hadn't told anybody about it yet.

This is the first version of Batman to address the black eye makeup under the cowl directly. In previous films, the makeup just disappeared when Bruce took his mask off. Matt Reeves stated, "I just loved the idea of taking off [the mask] and under that, there's the sweating and the dripping and the whole theatricality of becoming this character."

Matt Reeves stated that his version of the Riddler was partly inspired by the infamous Zodiac Killer, an unidentified serial killer who operated in northern California in the late 1960s. The Zodiac used ciphers in his infamous letters to the police, which made Reeves call him a "real-life" Riddler. In the film, Riddler begins his video saying, "This is the Riddler speaking," and the Zodiac began his letters with "This is the Zodiac speaking." The Zodiac also murdered his victims while wearing a leather suit and mask with glasses over the mask, just like the Riddler wears.

Continuity

When Batman takes his shirt off toward the beginning to the film, he has a large scar on his shoulder. The scar is gone later in the movie, when he appears shirtless while laying out the clues he's gathered on the Riddler case.

During the wide shot of Gotham City Hall (St George's Hall, Liverpool) 57:53, you can see a bus stop in the bottom right of the frame. This is a Merseytravel bus stop in Liverpool, and being in the UK, the bus stop is on the left hand side of the road, with the rectangle plate on top showing the buses that stop there facing the oncoming traffic.

When Bruce/Batman first gets on his bike his hands are not wrapped but when he gets to Wayne Manor to review the night his hands are wrapped like a boxers.

When Selina Kyle is cracking the safe she is wearing gloves. Later on when she is back in her apartment with Batman the audience can see that her nails are longer, which would not have been able to fit over the gloves.

In the finale, Batman saves people in the water by cutting the electric cable using the knife on his chest then falls in water. He gets out without the knife neither on his chest nor in his hand. The next scene he meets Selina and the knife is back on his chest.



Factual errors

The doctor tells Bruce the she's hoping the patient will stabilize. If he is not stable, he should be intubated and in an induced coma, not just sedated with an oxygen mask on his face.

The moment when Annika Kosolov's passport is shown on the screen. A birth year is marked as 1998 but social security number starts with 490, depicting that her year of birth is 1990.

When GC1 News plays Riddler's latest video (with the victim who has rats strapped to his chest), it uses subtitles for Riddler's voice. The subtitles misspell "judgment" as "judgement," which is incorrect in American English. However, the rule in English is that G can only be soft while preceding an E, I, or Y. This anomaly is derived from a misspelling in an early dictionary and has been propagated ever since. Both spellings are acceptable.



Audio/visual unsynchronized

Slight asynchronized dialogue (obviously dubbed in post-production) when Gordon says "You have any idea what kind of trouble you're in?" at 11:25.



Errors in geography

In the final shots when Batman and Selena go their separate ways on the bikes, as Selena drives under the arch towards the camera, the UK road marking for Give Way can clearly be seen on the left lane (from Selena's point of view). Odd production didn't swap for American markings.



Plot holes

Neither Batman, supposedly the world's greatest detective, nor the GCPD, seem to try and search for Riddler's apartment, despite the fact that the photos of the club are clearly taken from an elevated position, rather than from the street.



Character error

The forensics officer taking photographs at the scene of the mayor's murder uses the flash when taking photographs for evidence, even photos of reflective surfaces such as the framed newspaper pages. Any experienced photographer would use the ISO and aperture settings to take photographs without a flash, which would eliminate flash reflections and 'whiting out' of the area being photographed.

When Batman handles evidence at Riddler's apartment, Gordon dismisses his concerns by saying that Batman is wearing gloves. The chain of custody concerns go beyond simply leaving fingerprints. At trial, Riddler's attorneys could argue that Batman had tampered with or planted evidence. An experienced officer like Gordon would know all of this.

When the Penguin explains how "el rata alada" is incorrect Spanish and should be "la rata alada", he then says, "?No habla espa?ol, fellas?" But correct Spanish grammar would be "?No hablan espa?ol, fellas?" as he is addressing both of them: the verb should be plural.