Other mistake: Earlier in the movie at Geiger's house, Marlowe calls Chief Insp. Bernie Ohls of the District Attorney's Office and the six digits of Bernie's phone number are 122-145. At the very end of the movie,, he's with Lauren Bacall at Geiger's house and again calls Bernie Ohls. This time he dials the same phone at the DA's office but leaves off one digit, calling 12-145.
Other mistake: Marlowe tells Lauren Bacall to start screaming in 20 seconds after he leaves the room, she does and Lash Canino is outside and hears her. He runs into the house and if you look closely the prop porch railing almost falls over as he runs by because the crew did not attach it properly. Later we see it again and it's attached properly.