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.
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.
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. This is because Kravitz made the decision to grow her nails out during the pandemic to give her character "scary nails that look like claws".
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.
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.
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.
A city which is located at a lower elevation than that of the surrounding waters should have had better emergency plans.
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 español, fellas?" But correct Spanish grammar would be "¿No hablan español, fellas?" as he is addressing both of them: the verb should be plural.