Blasting It Out of Their Hands: Roland does this to gangster Jack Andolini. The gun, however, explodes into Andolini's face. Later, he shoots a gun and a knife out of different people's hands in the same encounter.
Decapitation Presentation: During the gunfight, one of Balazar's men throws Henry's head into the room to distract Eddie.
Did Not Do the Research: A doctor refers to Odetta as "schizophrenic" after seeing two of her personalities. Anyone who's graduated medical school should know full well the difference between schizophrenia and disassociative identity disorder (formerly multiple personality disorder).
In the 1960s (Odetta's when), multiple personality disorder was often confused with schizophrenia.
The Eighties: Eddie is pulled from the eighties by Roland.
Going Cold Turkey: Eddie involuntarily ceases to be a heroin addict when he's drawn into Roland's world, because there's no heroin there.
Half the Man He Used to Be: Roland drops Jack Mort under the same train that'd severed Odetta's legs. He gets run over the same as his victim, but several fatal inches higher up.
Love at First Sight: Eddie almost immediately falls in love with Odetta shortly after meeting her.
The Mafia: Balazar is a big crime boss in New York. When Roland "draws" Eddie, Balazar is using Eddie's heroin addiction to manipulate him into smuggling cocaine.
Malaproper: Roland can't pronounce words like "aspirin" or "Keflex" correctly.
Mundane Luxury: The taste of tuna and soda overwhelm Roland. (He's amazed that people smuggle drugs when sugar is free and abundant.) He's also shocked by people wasting paper, which is very rare in his world.
One Degree of Separation: Jack Mort is the guy who dropped the brick on Detta's head. And pushed her in front of a train. And pushed Jake in front of the car that killed him. Very pushy, our Jack.
Short Range Shotgun: A truly horrendous example pops up during the shootout in Balazar's office. One of the crime boss' mooks fires a shotgun at Eddie, and not only is the length of an office enough for the spread to be ineffective, but those pellets that do hit him merely sting. That's right, someone just on the other side of the room shoots Eddie in the chest with a shotgun, and it just stings a bit.
Writers Cannot Do Math: The dating of the segments with Odetta and Jack Mort is inconsistent. First, Odetta thinks that it's been three months since the assassination of JFK; that means it's February 1964. Not much later, it's stated that August 19, 1959 (when she lost her legs) was five and a half years before; that means it's February 1965. It's first stated that Roland entered to Mort's head at most a few weeks before he would've killed Jake; that means it's 1977. Later, it's said that a character saw The Terminator nine years later; that means it's 1975. Later, it's stated that Odetta lost her legs three years ago; that means it's 1962.
Also, Henry, Eddie's brother is a Vietnam vet despite still being a teenager in 1977 (two years after the war ended). This is possibly justified in-universe, since in later books, it's implied that this version of Earth is slightly different than ours.