When Lucy is harassed by the drunk guy and Ben comes to her rescue, they all bolt out of the bar and Mimi grabs all the money they'd made, cupping it in two big handfuls. When we see Mimi running out, she only has a small bundle of money in one hand.
Lucy's hair changes from short to long, and back to short in a short period of time.
Lucy gets up twice when Kit and Mimi get into a fight by the side of the road.
In the diner, the ketchup bottle disappears from Ben's hand for one shot, just before he puts it down.
In the diner scene while Lucy is figuring out if they have enough money, Ben is eating some food. Between shots, a piece of bread is in his mouth, then in his hand, then in his mouth again.
When Lucy calls her father from Louisiana, she dials seven numbers. You would have to dial at least 10 numbers to call Georgia from Louisiana.
Lucy is in the shower when Mimi flushes the toilet. This leads to Lucy complaining that this makes the water cold. But flushing a toilet draws away the cold water, which leads to the shower water being hotter, not colder.
When Lucy is on the phone to her dad and everyone is loading up the car outside the second hotel, Mimi is putting her stuff in the trunk of the car. You see Mimi look over at someone, shrug her shoulders and say, "What?" The directors were telling her that she was in Lucy's shot.
After Lucy finds out she is a mistake, she and Ben walk out of the bathroom to go talk to Mimi and Kit. In that scene, Mimi's shirt is lifted a little, revealing the white, fake pregnant stomach she was wearing.
When Lucy exits the shower with a towel wrapped around her, her bra strap is showing above the towel.
Kit is driving from the oceanside motel to see her boyfriend at UCLA when Mimi asks why they are on Melrose instead of going sightseeing. But UCLA is between the ocean and Melrose. (There's no indication they are lost.)