The Heisenberg hat was largely absent this season. Bryan Cranston was quoted as saying he took note of this and brought the hat back specifically for the scene with Gus to show the power Walt holds.
Running Gag: Walt has his windshield broken for the third time this season. Previous culprits were aircraft damage and Jesse (throwing a concrete block).
Goof: When Jesse is transported to the chicken farm the car stops in front of a black vehicle. The camera point of view changes and the black vehicle is missing. Also the sun shades changed, indicating that between arrival and exit some (real) time passed. Additionally the distance between the parked cars alters.
Andrea's mother is obviously disgusted finding Jesse and Andrea together. She walks out muttering in spanish "shameless S.O.B.s. I'm tired of it, sick and tired of it all...".
When Walter enters Gus' residence, Gus leads him to the kitchen. They pass by a tastefully decorated dining area. This is the first clue that children are present in the Frings household as there is a small children's table against the wall. More prevalent is the small red toy car on the floor highlighted by the lamp. Look closely, it is just like Jesse's car, the Toyota 4WD.
Skyler incorrectly states that married couples can't be forced to testify against each other. This is a common misconception about the spousal privilege. It doesn't extent to testimony about ongoing fraud/criminal activity.
Episode Title: Abiquiu is a very small town in the Rio Arriba County, New Mexico. One of the only points of interest is the adobe-built St. Thomas Church (made from sand, clay, manure and water). The famous artist Georgia O'Keeffe lived there for almost 40 years. In addition, it mimics the way "ABQ" sounds, the short form for Albuquerque.
Symbolism: At one point Jesse is standing on top of an unstable and rocking stepladder trying to swat the fly up high while Walt is trying to hold it steady. The stepladder can be construed as representing Jesse and Walt's current relations -- strained. Then Walt almost confesses about the fate of Jane: this could have been envisioned as a toppling of the ladder, but this doesn't happen.
Symbolism: When Jesse grabs a gas mask and plans to defy Walt's orders not to start cooking, the mask is clearly spray painted in certain areas with red paint, resembling the anatomy of a fly. Jesse's clothing also adds to the charade, as he's wearing a dark brown-greenish shade. Then Walt swats him with his lab-made swatter, further pushing this analogy.
Symbolism: The smoke detector light blinks red in the distance while Walt wakes up. Jesse often wears clothing with red in it. At the end of the episode, the same red light is super-imposed with an image of a fly.
This episode features the fewest cast members of any episode produced. Only Jesse and Walt appear. Only a few other laundry workers are featured.
Vince Gilligan admitted in an interview that Luis and Daniel Moncada went totally above and beyond anything he could imagine about what the characters of "The Cousins" would be. This is why they remained so far into the season. In fact, after this episode when the two characters were finished, Vince said every cast and crew member wanted their photo taken with the actors and spent hours doing so before they left.
Although the twin that appears has his legs amputated, in the previous episode where Hank pins him against two cars hard, there is no visible blood or indication of severe injury. Also this twin was pinned at just below the waist, not at knee level.
Episode Title: At the end of the episode, Hank is placed in the I.C.U. (Intensive Care Unit). The episode's title is a nice play on words.
This episode was nominated for two technical Emmys: Outstanding Directing for a Drama Series (Michelle Maxwell MacLaren). Outstanding Sound Editing for a Series (8 co-nominees from the editing department).
Gus is revealed to be from South America. Gus has been active for at least 20 years as Tio (Don Salamanca) has had contact with him for about this long as per the flashback in this episode.
However, in reality, it's very unlikely that Gus is from anywhere from Latin America, since his Spanish, although fluent, is not grammatically correct and most of the times what he says is a literal translation of the English phrase rather than a proper Spanish sentence. Moreover, his accent is the one of a English-speaking person, not one of any of the South American countries. Young Don Salamanca also seems not to be a native Spanish speaking person, although his Spanish not as awkward as Gus'.
This is very noticeable when you compare what Gus or Tio says with the cousins sayings (truly Mexican).
The cousins are revealed to be cousins of Tuco. Their names are Marco and Leonel.
This episode was nominated for two technical Emmys: Outstanding Cinematography for a One Hour Series (Michael Slovis, Director of Photography). Outstanding Single Camera Picture Editing for a Drama Series (Skip MacDonald, Editor).
According to Bryan Cranston in an interview, throwing the pizza (which was very real and very heavy) onto the roof took one take. And there's a split second where Bryan actually does a double-take, surprised at the result.
While filming the scene where the truck explodes, Bryan really only had one chance to pull it off due to the expensive nature of the shot. Bryan placed a line in the ground and told the brothers Luis and Daniel Moncada that once they crossed this line, the explosion would be triggered and to not flinch. They were a safe distance away, but with the long distance camera lens, they appeared closer.