Continuity mistake: A pile of drugs gets blasted up with powder flying everywhere yet there's none on the ground seconds later.
Factual error: When "some Frida Kahlo-looking asshole" is chasing Harley across the bridge during her close-up you can see that the cartridges are loaded backwards into the cylinder. (00:54:05)
Continuity mistake: When Harley has a tray of cocktails in both hands her friends are saying about her cheap looking gold chain...suddenly there's a close up of her holding the chain with one hand, then pans back to her holding the tray of drinks with both hands. (00:05:36 - 00:06:00)
Continuity mistake: When Cassandra is in Harley's apartment for the first time, the milk that Cassandra uses is capped in one scene and uncapped in the next. (01:01:00)
Continuity mistake: The egg sandwich was not sliced, but when Harley opens one end of the wrapper, it has been sliced (with the sliced edge facing outward). When the sandwich flies in the air and lands on the street, there are four pieces of roll, which indicates it was sliced. However, when sandwiches are sliced in half, the half is not turned around like it was when Harley first opened the wrapper and was about to take a bite. (00:13:08 - 00:15:46)
Continuity mistake: In the scene with the sprinklers in the prison Harley gets soaked. She walks into a different room and suddenly she's completely dry.
Continuity mistake: Detective Renee Montoya holds the evidence bag with the J necklace in a different way between shots.
Suggested correction: She's actually completely wet in another room, she just dries too fast in the process of fighting.