Continuity mistake: When Mike and Walt and Jesse are driving toward each other in the desert and they both spin out to avoid a wreck, Mike can be seen leaving his Cadillac, which is in the middle of the road/tire tracks, and the front wheels are in the tire tracks. In the middle of the scene, the Cadillac has moved to the right slightly, but is still in the road. At the end of the scene when the three drive off together, the Cadillac is seen off the road, having moved significantly to the right without a driver present. (00:15:15 - 00:16:45)
Factual error: In the opening scene for the episode, a character commits suicide by electrocuting themselves with a defibrillator. The device used was an AED (automated external defibrillator) which analyses the electrical rhythm of the heart and only delivers a shock when the heart rhythm is ventricular tachycardia or ventricular fibrillation. In this case, the device would not have delivered a shock as the person did not have both ECG electrodes attached and therefore would not have detected a cardiac rhythm. The person would also have had a normal heart rhythm.
Other mistake: There is no P-trap beneath the red sink in the Madrigal offices.
Hazard Pay - S5-E3
Other mistake: Jesse and his girlfriend and Brock are all apparently playing the video game, but when they show the TV it's only split screen so only 2 are really playing.
Hazard Pay - S5-E3
Continuity mistake: Skyler's salad at the car wash changes during the sequence. She gains pieces of lettuce after she starts yelling "shut up."
Continuity mistake: In the scene where Walter White buys his new car and pulls up the parkway at their house, the wheels are turned when he stops, but in the next close up shot, the wheels are straight forward. (00:02:00)
Factual error: The temporary paper license on the back window of Walt's new car has an expiration of 12 August 2012, the year the episode was released in our time. However, in the Breaking Bad world, it should still be 2009. (00:08:10)
Dead Freight - S5-E5
Plot hole: Preparing to steal methylamine from the train, Walt, Jesse and Mike measure off a predetermined distance from the railroad crossing, which happens to coincide with a handy arroyo, where they bury their tanks. Problem is that they couldn't have known that distance (calculated by knowing the position of the methylamine tanker car in the train) until Lydia told them. But she didn't call that info in until the night after they'd already buried the tanks.
Suggested correction: They were counting on the tankers being at the back of the train, far enough away and at a curved angle so that the conductors wouldn't see them, and the hoses they were using would have been long enough to reach the tankers on either side of the one they stole from. Their heist hinged on a lot of educated guesses and luck, especially because they would have had to abort if the tanker was at the front of the train, but being lucky doesn't make it a plot hole.
I'd have to respectfully disagree. When they paced off the distance to the trestle over the arroyo, they had a particular number in mind (814). It's not explained whether this number represented knowledge of how far back the tank car would be if the engine stopped at the crossing. But if it did, how could they have known that? Not even Lydia knew until much later. And why would they assume the tank car would be toward the back of the train? Lydia doesn't mention that. When she calls Walt, all she says is, "I've got it." And even if she were to tell him, at that point everything's in place for the heist to happen at the location where the tank are buried.
IIRC the crew contacted an expert on hazardous materials shipping for advice on the scene. Rail guidelines require tankers containing hazardous materials are at a minimum "six-deep", that is, six cars away from the engine. Lydia probably told them in advance how long the train would be in terms of cars, so they had a rough guideline for which three or four tankers could possibly contain the methylamine. From there, it seems like their hoses were long enough to get to any of the other cars.
The 814 feet was to ensure that the spot they chose would be far enough away from the conductors so as to not be seen. And they weren't assuming the tankers would be at the back, they were just hoping they would be. As I mentioned, if the tankers were at the front, they wouldn't have been able to move forward with the mission. Lydia told them they would only have 6 hours to prepare for the heist after she told them where the tanker would be. That wouldn't have been enough time for them to get an excavator out there and dig the holes for their own tanks to transfer the methylamine into, so they had to guess the best spot to do it ahead of time and hope that's where it would end up being.
Dead Freight - S5-E5
Continuity mistake: A little boy finds a tarantula at the start of the episode and picks it up, letting it crawl over his hands. In the overhead shot of his hands, it shows him letting it crawl up his left wrist and start to get on his sleeve. But in the next shot from in front, suddenly the spider is in the middle of both his hands crawling over them.
Dead Freight - S5-E5
Audio problem: The engine's horn sound constantly changes before the train is robbed. And when the train begins to move again, a railroad crossing bell is heard, even though the crossing ahead just has crossbucks.
Continuity mistake: Mike wrote 'Fuck You' horizontally on the paper but when Gomey read that, it is at an angle. (00:10:30 - 00:11:40)
Continuity mistake: At the dinner table, after Walt tells Jesse that this business is all he has left, he is holding his glass and spinning it around by the top with his fingers. When the angle changes to show his face, suddenly his hand is balled in a fist behind his glass.
Continuity mistake: After Skyler excuses herself from the table, Jesse looks awkwardly to the side after taking a bite of green beans. As he does from the front angle, his left arm folds in front of his chest and he puts it under his outstretched right arm holding his fork. When the angle changes to the side, suddenly his left arm is out holding his glass of water.
Say My Name - S5-E7
Audio problem: When Mike says all that left is to leave town, the audio in the over the shoulder shot stops but Mike's mouth keeps moving. (00:41:20)
Say My Name - S5-E7
Continuity mistake: When Hank steps in and presents the search warrant to Mike, he's holding it close with Mike looking down at it. When the angle cuts, suddenly Mike is leaning his head back like he's trying to look at it near sighted.
Say My Name - S5-E7
Continuity mistake: When Walt places the wire under his wrist strap its position keeps changing. Note the exposed wire in relation to the strap.
Factual error: When going over the logistics of the plan to kill the ten men in prison, Jack tells Walt that killing Osama Bin Laden was less complicated. Breaking Bad takes place over a period of two years, beginning with Walt's birthday in 2008, and ending on his birthday in 2010. Bin Laden wasn't killed until May of 2011. (00:15:23)
Continuity mistake: After Pinkman opens the bags filled with money he throws his gun along the floor. When it stops it points in a 3 o'clock position. When the angle changes it points in a 1 o'clock position. (00:41:00)
Visible crew/equipment: Walt just ordered to kill all Mike's witnesses in prison. While it shows one of them stop in front of the locked door and get killed by the other prisoners, a cameraman is reflected in the glass door.
Continuity mistake: In Season 4 we see Mike gets shot in the ear and and has a flap of flesh hanging off. In this episode, there are no marks or deformities on his ear.