Breaking Bad: Vince Gilligan On Why Walt Left Gale's Book In The Bathroom
"Breaking Bad's" Walter White (Bryan Cranston) is known as one of the most intelligent protagonists in television history, not only for his cunning plots and schemes but also for his immense knowledge of science and chemistry. As his brother-in-law Hank Schrader (Dean Norris) says in the very first episode, "Walt, you've got a brain the size of Wisconsin," and throughout "Breaking Bad," we see Walt use that colossal intellect to build a meth empire from the ground up — cooking a form of methamphetamine that is purer than any other in the entire world.
Because of how unbelievably smart Walt is, it seems somewhat odd that his ultimate downfall came from a misplaced piece of evidence that he left in his bathroom – a book of poetry gifted to him and signed by fellow meth cook Gale Boetticher (David Costabile), which Hank discovered on the toilet. When asked as a New York Times panel in 2013 how Walt could have done something so foolish, series creator Vince Gilligan replied, "my personal take, and one to be taken with a grain of salt, is that he neither wanted to be caught nor was he particularly arrogant in that moment ... he just, um, was not as cautious as he should have been. I think it was a mistake, pure and simple."
Gilligan went on to say that he believes Walt either forgot about the inscription in the front (which linked him to Gale Boetticher) or never even knew that it was inscribed. However, he also said that the entire situation is up to interpretation by the audience, and any answer about why Walt left the book behind could possibly be the truth – saying that "this show is yours [at] this point as much as it is ours."
Walt has left evidence behind more than once
Although it might seem like a long shot that the incredible brain of Walter White could have forgotten about this incriminating book (or never even realized it was incriminating to begin with), there are multiple examples throughout the series of Walt being overly confident in his lies – to the point where he forgets caution and leaves evidence behind for the police.
A few notable examples include the gas mask that he leaves in the desert in the very first episode, as well as the beakers and flasks stolen from his high school (both of which are found by Hank but linked to the wrong person), the RV that he first cooked in (which he had to scramble to hide once Hank discovered its existence), and the security camera footage of himself and Jesse Pinkman (Aaron Paul) stealing Methylamine.
The book in question actually causes Hank Schrader to start piecing all of these little bits of leftover evidence together in the Season 5 episode "Blood Money," – eventually proving beyond a doubt that his brother-in-law is the infamous drug kingpin known as Heisenberg, While it might frustrate some fans to learn that this crucial pilot point might have just been a mistake by the "genius" Walter White, it certainly seems like there are plenty of prior incidents to support Vince Gilligan's theory.