When Walt and Jesse are in the desert arguing about distribution, the close up shots shows that side of the RV completely shaded, while the distance shots show that it's in the sun.
As Walter backs out of Tuco's office, the object held in his right hand changes. At first it was a translucent bag clearly holding the explosive, but it switches to a poorer quality prop with a vague yellow substance in it.
The blast in Tuco's office is powerful enough to propel the air conditioners onto the streets below, yet Walter who is right under the explosion suffers nothing more than a bloodied nose.
When Walt tells the class to read from chapter 7 and turns his back to the camera to leave the classroom, the fabric pins used to alter the fit of his sweater are visible.
When Walt and Jesse are arguing in the desert about finding a wholesaler to move more meth, there is an obvious lens reflection.
During the game of Texas hold 'em the sequence is wrong. After Hank deals the turn, Walt Jr checks, Skyler checks, and Marie bets. Then Walt and Hank call without either Walt Jr or Skyler having to call Marie's bet, Hank deals the river. Then Walt Jr, Skyler, and Marie all fold when they simply could have checked. Also because Marie opening the previous bet, it is strange that she all of a sudden folded without reason.