Other mistake: Twelve seconds into the intro, the shot of the store with the name Adrian Grenier above it is mirrored. Notice the reversed lettering in the signs. (00:00:10)
Suggested correction: Does something in the intro count as a mistake? Even still, the signs could be facing the inside of the store on purpose, making it look like a reverse image from the outside. Just to the right of the store with Adrian Grenier's name on it, we see a sign for Pizza displayed correctly.
I would say, for this type of intro, it should be considered a mistake. I'd call it an "other mistake" as it wasn't done deliberately. There's no way the reversed imaged signs point into the store. The photo store has a solid sign that's not inward facing, with the word "Kodak" flipped. The neon signs facing outwards are also flipped. And the pizza signs are also incorrect. The p and z's are flipped as well.
You're absolutely correct, I do see the reverse print on the photo store. Oddly enough, one of the pizza signs is displayed correctly, however.
Visible crew/equipment: In just about every scene of the show where actors are wearing sunglasses, the large lighting equipment can be seen.
The Script and the Sherpa - S1-E5
Continuity mistake: When Vince and Eric are smoking weed with the older guy in the car, the older gentleman, Scott, is smoking from a joint less than an inch long, and proceeds to pass it to Eric. Eric, in turn, takes a hit and hands it to Vince, only the joint is now closer to two inches long.
The Script and the Sherpa - S1-E5
Continuity mistake: When Eric is taking to the girl before she enters the pool, his sunglasses move up & down between shots.
The Script and the Sherpa - S1-E5
Continuity mistake: When Turtle is thanking Christy, the box jumps from his right hand to his left.
Factual error: In season 2, they spend a lot of time at a Malibu Beach house. There are a few scenes across a few episodes when they are headed from Malibu into Los Angeles, but the scenes are shot on the coast in El Segundo, roughly 30 miles out of the way and definitely not a straight shot from Malibu.
Continuity mistake: About 3 minutes into the episode the guys get off the plane and the shot is straight on. Johnny Drama is saying his line. The shot changes to them on their left and Vince says his line, continuing the conversation. The people walking behind them from the front shot changes to completely different people when the shot changes to the left side. (00:03:00)
Continuity mistake: When Eric is talking to Harvey Weinstein in the airport bathroom, at the beginning of the episode, the length of Weinstein's cigarette changes several times. Ash can also be seen dropping, only to reappear (with the cigarette maintaining its original length) in the next shot.
Continuity mistake: When Vincent is dining with Mandy Moore at The End of the episode, while he's at the table he has a 5 o'clock shadow, but as he leaves the restaurant he looks freshly shaved.
Other mistake: In the opening scene, Ari calls Eric at 5:42 a.m. There is way too much sunlight coming through both of their windows for it to be that hour.
Continuity mistake: When all of them go for a ride at The End of the episode, when the camera is at front they are actually sitting in the roller coaster, but when the camera is at their back, everyone is replaced and stand-ins are used.
Strange Days - S3-E7
Visible crew/equipment: When the guys are talking to Ari via cell phone from their black SUV, if you look at the black area between the front and back windows, you can see the reflection of the camera filming The Scene from outside the vehicle.
The Return of the King - S3-E17
Continuity mistake: When the boys come back from the track it is implied they bought a horse and attached a horse carrier to their car for it. You see it in an outside shot. But when they're filmed inside talking, you can see a lot of the rear window of the car and no horse carrier is seen.
Continuity mistake: When Billy slides the Medellin script on the table back to Vince and E the word "Medellin" goes from upside down to right side up. (00:11:00)
Continuity mistake: When Eric gets a call from Ari while getting shaved, the amount of shaving cream on his face changes between shots, going from fully lathered to partially shaved, and back again.
The WeHo Ho - S4-E6
Visible crew/equipment: When Turtle is in the kitchen talking to the guys about his cousin, we have a tracking shot of him going to the table and then returning to the bar. If you look at Vincent's face during this shot, you can see the cameraman's shadow as he passes him.
Continuity mistake: In the first segment where Ari is street racing Adam Davies, he overtakes the same silver Saturn Astra twice. He also passes a black car that changes into a large silver GM SUV in the very next shot.
Redomption - S5-E6
Continuity mistake: When Johnny and Turtle are talking at The End of the episode, right before Turtle quits as Johnny's assistant, the same extra is seen walking in the same direction 3 times.
Continuity mistake: Ms. Ari Gold is on the tennis court and she is talking on a phone that's upside down. Then the shot cuts and the phone is in the right position. (00:08:15 - 00:08:55)
Continuity mistake: When Vince is standing in front of his friends in the hospital, his right eye itself is bloodshot and there's a lot of blood on the side of his face. When he turns to face the cop who's holding the bag of coke, the contact lens to make his eye looked messed up is gone and there's hardly any blood on his face.