When Rusty is dining with his wife and son in the restaurant he asks his son, who is holding a glass of milk, a question. His son answers immediately holding his knife and fork. It also happens the other way round when the son speaks to his father.
On several occasions, Rusty Sabich refers to his boss, Raymond Horgan, as Raymond Horrigan.
Carolyn's name is spelled "Polehemus" on the bond slip, while in the credits it is spelled "Polhemus".
Bottle of Dewar's Scotch on desk turns clockwise between shots.
When Rusty is discussing the case in Stern's office, there is a small figurine of a deer on the end table holding the lamp. When the camera angle changes to Rusty sitting next to the same table, the figurine is gone.
Rusty takes the fifth during a grand jury inquiry. The State of Michigan uses preliminary hearings, not grand juries, to determine whether enough evidence exists to try a defendant.
Sandy and his attorney visit the former DA. Raymond, as his new office. They discuss his upcoming testimony to the grand jury. In reality, this is witness tampering and would never be done by a defense attorney at that stage of a case.
When Rusty is walking out of the court after the trial he is besieged by reporters. One of the reporters is holding up a portable tape recorder but there is no tape in it.
A reporter thrusts a small tape recorder in front of Sandy Stern outside the courthouse, and it is possible to see that there is no tape in it. While this may be thought to be a possible character error, compact audio (and you may better remember VHS video) cassettes have a tab you can break to prevent accidentally recording over previous work. Thus, without the tab, the device would not be able activate the recording function. If a cassette is not in the device to begin with, then it is as though a tab is not present and wouldn't be able to start recording. Therefore it is very unlikely to be a character error. Furthermore, if the tape recorder spools were not turning, then that is further evidence of a mistake by the filmmakers.
During the trial, the attorneys are allowed to walk up close to the witness that is testifying. In reality, counsel would be behind a lectern or podium and can only approach a witness with permission of the judge.
Ray Horgan, Rusty's boss and DA insisted he wanted him to handle the Polhemus murder case. However, he later testified that Rusty volunteered to handle it. That was either perjury or an honest error. In either case, the defense didn't challenge this testimony that suggested Rusty was looking for the opportunity to cover up his supposed guilt.
When Rusty is working late with Stern's assistant, he gets a phone call from his "uncle", but it's actually Lipranzer calling him. Rusty says, "look Greer, we're working to keep the glass out of evidence". He should have called him "Lip", not "Greer".