When Aldous and Aaron are in the limo, on the way to the Today (1952) show, the limo passes some buildings on First and Second Avenue twice.
When Aaron and Aldous fly to Vegas, they take off in a Boeing 757 and land in an Airbus A320 with a different livery.
The "Geoffrey Scene" occurs at dusk. When Sergio chases Aldous and Aaron outside, it's clearly afternoon.
In Aaron's POV camera shot of his tongue, lipstick appears around the tip of the tongue before the dancing girl kisses it.
When Aldous and Aaron leave London to fly to New York, a twin engine Boeing 767 is shown. When they land in New York, a four engine Boeing 747 is shown. London to New York flights tend to be nonstop, so they wouldn't have changed planes.
In Las Vegas, the view out the window clearly shows the circular hotel tower of the old Sands hotel and casino, which was imploded in 1996.
When Aaron calls Daphne from the club and he starts to argue with her, she is drinking a beer and pacing in front of the kitchen window. Several members of the film crew are reflected in the window.
In both the Today Show segment and the concert at the Greek, the film crew's Steadicam (veteran operator Chris Haarhoff) with Panaflex on board can be clearly seen shooting from the crowd.
When Aldous is performing outside on Today (1952), a blue cherry picker behind him has a distinctive Panavision 35mm movie camera and crew members on it. Several shots from the camera are used in the sequence.
When Aldous Snow is picked up at a London hotel, the car picking him up is facing so it would drive off on the right side of the street, which is correct for the U.S., not England.
Aaron and Aldous fly from London to New York via Stansted Airport, which has no passenger services to any American city.
During the drive from Vegas to L.A., the mountains behind Aldous Snow change and become darker, as if the sun was setting, within a few seconds.
When Aldous enters Aaron's house for the threesome, a boom mic is reflected in the glass of the door.
Sergio asks Aaron, "Do I look like 'African Child'?" but means to say, "Do I look like I like 'African Child'?"
When Aaron is at the hospital asking Daphne to get coffee, some X-rays are in the background. The lower one (chest X-ray, lateral view) is upside down.
When they start fighting in Las Vegas, Sergio and Aldous' dad punch each other directly in each other's hands, and appear to be genuinely hurt.