When Levene enters and exits the Spannel house, the rain is pouring immediately outside the front door. But after he exits the camera pulls back to reveal he is on a large roofed porch. So the rain would actually be falling some distance from the door.
After the police interview Alan Arkin puts on his coat and leaves the office. In subsequent scenes his coat can be seen draped over the back of the chair at his desk. The coat appears and disappears in Jack Lemmon and Kevin Spacey's confrontation over the office burglary.
Right after Williamson messing up with Ricky's deal with a client, Shelley Levene appears in the background teasing him. However, in the previous moments he was in the office talking to the detectives and there's no indication that he got out of there at any point.
George's hand is on his chin when the camera is behind him during a conversation with Ricky, but when the angles are changed his arm is flat on the desk.
The neon sign on the restaurant across from the office has 4 or 5 of its letters on each line not operating. In the scene where Aaronow and Moss are in a car across from the restaurant, all of the letters on the sign are illuminated, as can be seen out the window of the car behind Moss. When they get out of the car, the letters are, again, not working.
Stealing the list of references from Williamson's office constitutes the crime of burglary, but the police describe the crime as robbery. This same mistake was present in the original play.
The cops would not make such a big deal out of a common burglary. They'd make a report and leave. They couldn't and wouldn't conduct a day-long, on-the-spot, investigation while rudely accusing the employees of being guilty.
AIDA is described as standing for Attention Interest Decision Action, whereas it really stands for Attention Interest DESIRE Action. The one Baldwin quotes is nonsensical because the Action is the Decision.
David Mamet's play, upon which this film was based, is set in Chicago, but the movie version is set in New York.
Roma was never actually told that the leads were stolen.
In the beginning of the movie Al Pacino's character (Roma) and Jack Lemmon's character (Levene) sitting at the bar and the latter calls the former "Al" with his real name instead of his character's name.
After George tells Ricky that the phones were stolen, in frustration Ricky sums up "They stole the leads, they stole the phones..what am I going to do this month?" Up to that point, no mention of the leads being stolen had been made, just some of the contracts.
Shelley pretends to be a client from AMEX when Lingk comes into the office. But when Roma first meets Lingk at the bar, he's sitting with Shelley. Surely Lingk would have remembered who he was.
It makes sense that Roma would get the drunken loser in the bar to sign over lots of money for unseen land, but the loser's wife would not cook dinner for Roma, a total stranger late at night, sign the contract, and then demand that her loser husband go get the money back early the next morning.
Shadow of camera crew visible on the train in the closing shot.
Although the play was set in Chicago and the movie in New York, references are made in the movie to places around or near Chicago. Levene refers to the meeting in Kenilworth which is a suburb of Chicago (Kenilworth is also a New Jersey suburb of New York City, near Newark Airport). Levene also mentions fishing for muskie in Wisconsin. Moss gets angry and says that he is "Going to Wisconsin." Characters in New York wouldn't reference such places.
At the end, Roma is screaming at Williamson because Williamson has interfered with Roma's effort to mislead a potential client. A police office is standing by taking it all in. However the officer takes no action despite what constitutes ready admission of a serious attempt at fraud.
GGR would only need to cross reference the "good" leads with who sold to them to uncover who stole them. The movie supposes the company has no idea what leads are in the metal box.
Update - this is not a plot hole. The thief did not plan to sell land to the good leads. Instead he (they actually) sold the leads to a different company.
Update - this is not a plot hole. The thief did not plan to sell land to the good leads. Instead he (they actually) sold the leads to a different company.
When Levene tries to convince Williamson to go along with his plan to give him some of the Glengarry leads, the boom mic operator is reflected in the office window.