These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: Louis Roulet is a rich, spoiled sadist who believes he can do whatever he wants. Roulet enjoys beating on women, particularly prostitutes, as he knows they'll never be believed over him in court and he has the best representation money can buy. Roulet is soon revealed as the real murderer in a case the Amoral Attorney protagonist, Mickey Haller, had defended years ago, and Roulet is positively gleeful over an innocent man rotting in jail for his crime. Roulet keeps Haller as his defense by threatening him, as well as his ex-wife and young daughter, knowing Haller is obliged to do the best for his client. Haller puts an informant on the stand to acquit Roulet of the assault, but the testimony puts Roulet under suspicion for his previous murder. In a rage, Roulet later makes his way to Haller's ex-wife, intending on murdering her and her daughter.
Harsher in Hindsight: The defendant Roulet describes a homosexual couple who came to his accuser's rescue as "two faggots". Haller's investigator, Levin, clarifies that it was a homosexual couple who lived next door, to which Roulet vehemently replies, "Like I said, the faggot couple!" Levin mutters under his breath, "I stand corrected. The faggot couple." It is somewhat Played for Laughs, but later it is revealed that Levin is gay.
Moral Event Horizon: Mary Windsor kills Frank Levin to protect her Complete Monster of a son from going to prison and later tries to kill Haller for turning against Roulet and trying to put him in prison.
What The Hell, Casting Agency?: In the book, Haller is half-Mexican and grew up in Los Angeles. Matthew McConaughey has neither of those attributes and maintains his Texas accent but, beyond that, he nails the character perfectly.
The Woobie: You kinda have to feel sorry for Minton. He is just completely outclassed by Mickey, he wants to do the right thing, and, oh yes, Roulet is actually guilty. The film has a shot where he's clearly realizing just how badly he's been screwed. Even the fact that it's Haller basically inverting the knife trick Minton played on him earlier doesn't help.