When Randy is trying to pry his photo from the wall in the doctor's office, he causes most of the other photos to fall off the wall and leaves a huge hole where his photo was. A few seconds later, the other photos are back up and the hole has repaired itself, with only some glue residue remaining where his photo was. The audio commentary mentions that this is the result of the scene being created from several takes.
When Randy is leaving the doctor's office, the hole in the wall is gone.
At the end of the episode, the doctor arrives for a date with Natalie and brings her flowers. Throughout the scene, Natalie alternates between holding flowers and not holding them.
When Randy is trying to remove his picture from the wall in the dermatologist's office, the picture below his is straight, crooked, and straight again in subsequent shots.
At about 33 minutes, Randy Disher tears a picture from the wall of a doctors office, revealing the wooden lathe behind the plaster and dislodging a number of other pictures. Moments later, Randy hands the picture to the doctor and we can see that the wall is miraculously intact. Just a few blobs of blu-tack where the picture was. All the other pictures are back on the wall.
When Monk and Natalie are in the balloon and Mandy Bronson opens fire on them, the balloon starts to descend after only a few bullet holes are punctured in the skin. In real life, 2 or 3 bullet holes would not cause the balloon to come down, The hole would need to be much bigger, or more bullets would have had to been fired.
Obvious stunt double when the balloon is crashing - the stunt double's hair is much thicker.
When Randy is looking at Steiner's appointment book, he notes that at last New Year's Eve, Steiner played a private party for Mandy Bronson. December 31, 2005, was a Saturday, but the book shows it as a Sunday. Obviously, this is a 2006 appointment book.
When Derek Bronson is playing the piano, his hands remain in a very short range of keys on the piano, mainly below middle C. At the same time, the music heard is playing up and down the keys, well above the range that Derek's hands are seen playing.
[36:34] When Mandy Bronson shoots at Natalie & Adrian in the hot air balloon, the first shot doesn't recoil or produce any muzzle blast.