When Julia first gets the knife from the chair, it has a chrome-like finish and a plain spine. Just after passing the spectres that jump from the balcony, it changes to a knife with a matte edge and a saw on the spine. The knife then changes back to its original style afterward.
When Julia is stopped by the New English sheriff, she opens the back passenger door and gets in behind the sheriff. She closes the door behind her and hands him her license and registration. After they talk and she goes to exit, she opens the same back passenger door by using the inside door handle. Police cars are made to have "back seat jails" and thus do not have inside door handles in the back seat, to prevent arrested individuals from being able to escape. She would have had to wait for the sheriff to open her door from the outside.