At 40:12, the tool in Catilina's hand changes color without him moving.
At 21:47, Julia Cicero's voice changes mid sentence: "I sent a letter to you last night. A childish letter", then it goes instantly deeper with "and I want it back before you read it" revealing ADR work.
At 21:40, Catilina's character says the phrase "Holy Jesus Christ!" in amazement. Yet, within universe, the city of New Rome stems from a culture based on Roman Mythology (example: 54:47, the dedication to Vesta; 01:55:51, someone says "The will of Cronus", or at 01:56:49, a statue of Saturn is displayed prominently, while there are many more depictions of Roman deities). In this universe, Christianity doesn't exist. There's no reason Catilina would use the phrase "Holy Jesus Christ!" and in such context.
The security video of Cicero entering Ceasars office is supposed to be two different cameras as indicated by the small text in the upper left corner. It is just the same footage flipped and slightly tilted.
At 34:37, Fundi drives the car with Catilina in the backseat while in a car chase. Yet when Fundi turns right with a very pronounced turn of the wheel, in the back, Catilina barely even moves, and the background outside the car does not change.
Throughout the movie there are many moments where the hand movements jump between cuts.