When the shooting first starts, Walt dives down in the back seat towards the floor and his glasses fall off. After the shooting stops and Jack begins talking to Hank, Walt appears in the back window of the SUV with his glasses on. With his hands cuffed behind his back, there is no way he could have retrieved and put on his glasses back on.
In the flashback scene before the title, Walt is speaking with Skyler over the phone after his first cook. She is still pregnant, but has the short hairstyle from later episodes rather than her long hair from the first couple seasons.
Skyler refers Holly as an 18-month-old baby to APD as Walt takes her away, even though she was born in February 2009 and this episode takes place in March 2010.
When Walt and Skyler are fighting over the knife, Walt is slammed against the wall and two decorative plates fall onto him. However in the next shot, only one of the plates has fallen.
When Walt leaves Holly at an Albuquerque Fire Station, 2 firemen are playing chess. The fireman playing White moves the King one square to the left. However, in the very next shot, the King is back in the corner of the board.
The coordinates of the hidden barrels were accurate to the nearest second (of degrees longitude and latitude). At around 35 degrees North, there is about a 18 meter distance between each second. It was therefore quite lucky that a barrel was under the spot where Jack's gang first started digging.
(at around 32 mins) When Skyler and Walter Jr. arrive back at the house and see the truck, the cameraman is reflected in the lower corner of the driver's side door.