Revealing mistake: Walter is in the basement and slides two bottles of water and a plate with a sandwich across the floor to give to Krazy-8. Right before he slides the plate across the floor, the camera wobbles slightly. (00:28:25)
Revealing mistake: When Jesse puts Emilio's dead body in the bathtub and we see a view from below, Emilio blinks. (00:42:27)
Revealing mistake: Emilio's eye twitches when the gun is dropped on the bottom of the bath next to his head while he is supposed to be dead. (00:42:54)
Revealing mistake: When Hank is summarizing what happened at the junkyard, you can see the big dead guy breathing. (00:42:00)
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)
4 Days Out - S2-E9
Revealing mistake: There are no water cooling tubes attached to the reflux condensers. Reflux condensers do not condense without cooling. (00:15:40)
Revealing mistake: When Mike is putting on the second glove to clear up the evidence in the bedroom, Jane's eye can be seen twitching briefly, even though she is supposed to be dead. (00:06:20)
Box Cutter - S4-E1
Revealing mistake: When Skyler walks down the hallway she stops outside Walt Jr.'s room, however the shadow on her chest keeps moving after she stops walking. (00:11:50)
Box Cutter - S4-E1
Revealing mistake: In the scene where Hank is on his laptop bidding on a mineral on 'Mineral Emporium', the address bar shows 'C://.' which means the web-page is in his own documents on his laptop. No way he can bid on a mineral if it's not online! (00:24:15)
Chosen answer: It is part of the ritual for la Santa Muerte. It is a sign of humility and sacrifice.
djm