Revealing mistake: At the end of the episode when Tuco shows up at Walter's house in the backseat of Jesse's car, he tells Walter to get in. As they drive off, the shot pans out to show the street sign across from Walter's house. The sign says Piermont, which is the real name of the street. In the show, the Whites live on Negra Arroyo Lane. (00:48:00)
Factual error: Hydrofluoric acid is so dangerous that no high school chemistry lab in the US would have a thimble full of the stuff around, let alone gallons. While it's incredibly toxic it's also a very poor choice for getting rid of bodies, which Walt would know.
Factual error: When the planes crash over Albuquerque, when the bear is falling towards Walt's house, there is a quick shot of Albuquerque suburbia and mountains. Two major streets are visible, the one on the right is Eubank Blvd and the one in the lower left is Wyoming Blvd, both which run north and south through the city. This means the shot is facing north. There are no mountains immediately north of Albuquerque as shown. The closest mountain range, the Sandia Mountains, are on the east side and wouldn't be in that shot. The closest mountain range in the north are the Jemez Mountains, which are 40 miles away. They would barely be visible in that shot (they would look like blue hills in the distance).
Other mistake: When the bear is falling through the sky after the plane crash, it is shown through its point of view. When it starts falling, a shot of northern Albuquerque is shown but when the bear turns over, suddenly it is facing the east. Eubank Blvd is a major north and south street, is seen in the shot of the north. In the latter shot, Candelaria Rd, which is a east and west street is visible. When the bear spun over, it should be showing Eubank Blvd going south.
Continuity mistake: When at Tuco's house, Jesse is first shown emptying his pockets and then getting everything back, even going as far as showing the clean table at the first timestamp, but when he's back at his car at the second timestamp, he doesn't have his keys, supposedly left at the table. (00:32:23 - 00:43:24)
Other mistake: Throughout the show, during the into credits, people's names have 1 or 2 letters replaced by green characters to symbolise elements from the periodic table. However, Michael Slovis has the 'Ch' highlighted. There is no 'Ch' on the periodic table. (00:03:20)