Audio problem: When Walt yells at Jesse through the lab's entrance door, the sound is very muffled, as if the door is a major insulator of sound. However, later, when Jesse yells at Walt through the same door, the sound is much clearer, and hardly muffled at all. (00:22:15 - 00:23:55)
Audio problem: After Hank and Gomez separate Jessie and Walt after he's arrested, Hank tells Gomez that "I'll call the Tribal Police on my way out, let them know we're here." During the middle of this line, the shot cuts to Walt and you can distinctly hear the sound of a microphone picking up the actor breathing on it as he recorded this line in ADR.
Audio problem: After Walt Jr and Skylar leave the room, Marie starts to leave. The camera is focused on Hank once she walks off screen and you can hear the sound of the door closing behind her. It then cuts to showing her suddenly just getting to the door and opening it to walk out.