When Dawn Campbell rushes onto the advertisement stage next to Heather and confronts Daryl, Heather's coat is on in one shot but in the next shot, her coat is off without Heather taking it off.
When Brad is speaking with Bernard and Vivian in his office (near the end of the film), the football changes position after he sets it down on his desk - in one shot you see the strings and in the next, you don't.
In the Huckabees' headquarters, when Brad interrupts Albert's poem-reading, Tommy yells and points with his left hand in the wide shot. Cutting to a closer shot of Tommy and Albert, he is pointing with his right hand.
While Brad is on the grass crying, the wet spots on his shirt change with every shot.
After Caterine takes a Polaroid picture of Brad she holds the camera with her right hand. The next shot of her she has her arms crossed, and the shot after that she is holding the camera again.
"Ludwig van Beethoven's String Quartet #14, Op. 151" is mentioned in the credits. There is no Op. 151. String Quartet #14 is Op. 131.
Most cars in the movie have obvious "prop" license plates (with blue and white shading, and no State name, as if to obscure the intended setting.) However, numerous cars are seen to have California plates - often cars not under the control of the production team, for example, driving by on the roads. In one scene in the parking lot, all of the cars in the "background" have California plates, all of the cars in the "foreground" have prop plates.
Near the end of the movie when Albert clambers onto the rock beside Tommy the sound betrays the fact that the rock is made of plaster or fiberglass.
In the flashback where Brad and Albert are talking in the restaurant Brad tells him his girlfriend liked Albert's "poem about the rock". This is impossible because Albert first read that poem after saving a piece of the marsh at the beginning of the movie so at the time of the restaurant conversation, the poem had not yet been written.
When Vivian and Bernard are inside of Dawn and Brad's house after rummaging through the trash, the boom mic is visible in the reflection of the yellow teapot as Dawn pours it.
As Bernard discusses with Albert how his nose has no beginning and no end, you can see the boom mic in the reflection of the sunglasses on top of Vivian's head just as the scene ends.
When Bernard hands Vivian the phone for an emergency call from Tommy, the phone is in the right direction. When Vivian receives it, however, the phone is upside down and Vivian begins talking into it without flipping it around.
When Tommy's wife is leaving him, Bernard shows him a picture of the universe. He looks over to the left side of the picture when pointing out "our galaxy." However, in Tommy's next line, he points to the right side of the picture and says, "There's us over here."