When Hudson and Sara are in the car after being in the shop where she sees him steal a pen, the car seats visibly have headrests. Then when they start shooting the scene from behind, there are no headrests, as they would have blocked the actors' faces.
When Hudson and Sara argue outside the grocery store, the woman in red passes them twice, then an older man with sunglasses passes them twice.
When Hudson visits Sara's apartment for the first time, Sara places the broken turtle on the arm of the sofa before Hudson calls her cute. In the next moment, Sara says, "You think I'm cute?" while still holding the turtle.
When the stripper removes her pink G-string she kicks it off screen to her left with her right foot. When the camera angle shifts back to the opposite side of the stage the G-string is clearly visible next to her right foot. The same problem occurs a few moments later when the camera (from behind Hudson and Sara) shows her seated on the stage and the G-string is nowhere in sight, but when the camera shifts across the stage (facing Hudson and Sara) the G-string is next to her.
In the film's final scene when Sara is picking Hudson up from his favorite spot, it is supposed to be 4:45 a.m. and deserted, but the intersection in the background is clearly busy.
Just before Hudson and Sara get to the strip club, it's visible through the back window that the car is turning right, but he doesn't move the steering wheel at all to turn right.
When Hudson receives a phone call from Sara right after he has taken his second prescription of medication, the phone has no signal, meaning he couldn't actually receive the phone call.
In their first restaurant scene together, Hudson's sleeves alternate from being pushed up to his elbows to full length.
In the car after Hudson shoplifts the pen, the reflection of a crew member is visible in the car window.
After Hudson shoplifts the candy and he and Sara argue outside the store, Hudson's microphone is visible inside his shirt. The bump where it was taped into place is visible.
After Hudson steals the sneakers, he is shown running down a brick walkway past a sandwich sign for a nail salon. The phone number on the bottom of the sign has a 604 area code, which is for the lower mainland of British Columbia in Canada, not for the Los Angeles area, in which the story is set.
The car salesperson tells Hudson that there are "4.2 feet of cubic space back here," implying that the trunk is only about a foot high, a foot deep, and four feet wide (1 foot x 1 foot x 4 feet = 4 cubic feet)... a ridiculously small amount of space for any trunk.