Continuity mistake: In the scene where the shootout starts in the previous episode, Walter is handcuffed in the back of the SUV and trying to get to the floorboard to avoid the gunfire, and his glasses eventually fall off. After the gunfight when he is yelling at Jack from the back of the SUV, his glasses are back on his face, which would be hard to do handcuffed.
Continuity mistake: When Walt is sitting on the overpass it is clear that his car is parked on the part that straddles the median between the lanes, but when the shot is inside his car the view appears as if he is parked directly over the right lanes of traffic.
Continuity mistake: When season 1 left off, at the very end of the last episode, Tuco examines the blue meth seriously and says, "What is this shit? This is blue." At the start of season 2, the scene is repeated, only when Tuco sees the blue meth, he laughs and then says "What is this? It's blue." Even though its supposed to be the same scene, the dialogue is slightly different and Tuco's demeanor is completely different.
Continuity mistake: When Pinkman and White are having breakfast in the diner, the items on the table keep changing in each shot. Specifically, the jelly, the milk, the cup with the cream and, most noticeably, the rolled napkin with the cutlery inside: Sometimes folded, others opened.