Revealing mistake: Look at the stuntman who stands in for Tony Shalhoub when the balloon crashes and the basket scrapes and bumps along the ground. He is about fifty pounds lighter than Shalhoub, looks nothing at all like him and his hair looks like a Harpo Marx fright wig dyed black.
Revealing mistake: In their efforts to hide Gerald's pet mouse from the hospital staff, Randy and Natalie toss the rodent back and forth and alternate hiding him in their pockets. But every time he's tossed, Devo the Mouse gains weight. In fact, Devo's (stuffed?) stunt-mouse double is at least twice Devo's actual size. (00:27:00)
Revealing mistake: In the scene where Darwin and Monk are in the kitchen and Monk calls Dr. Kroger. Darwin pulls the phone out of the wall, but there is no line from the phone to the jack in the wall.
Revealing mistake: During the fight in the kitchen, piles of plates are knocked to the floor. The plates that we see hitting the ground all remain intact. Nevertheless, we hear the sound of plates smashing, and when the aftermath is shown, there is broken crockery everywhere. Clearly the plates used were made of plastic or some other unbreakable substance to minimise injury to the actors and stuntmen.
Revealing mistake: When Monk and the others are examining the crime scene, the "corpse" can be seen breathing (his abdomen is rising and falling) and blinking. There are various shots in this scene taken from behind the body looking into the room, and some of these are pulled back so that the body is visible while others are zoomed in so that it is not; this is not a mistake, but suggests that maybe the actor was told he would not be visible in these shots and so did not need to hold his breath.
Revealing mistake: When Monk steps in front of the limo to stop it from leaving, on the bottom right of the screen there's a black line that doglegs to the right (seen over Monk's coat sleeve). It's like the camera was cracked or something was stuck to it. When the camera angle changes it's gone, but is there where the camera is back on Monk.