When Perry and Paul are in the plant talking to Joe, Joe states that there is liquid ammonia in the tank, but the gauge is labeled nitrogen.
When Sylvia Lambert is seated on the witness stand her fur stole is on her shoulders in close-up shots and draped on her forearms in distance shots. While she is on the witness stand the camera switches to the lady who she had been sitting next to and her stole can be seen; obviously a shot from when she was sitting there.
When Sheriff Ramsey, while on the witness stand, told Mason that the victim was struck on the left side of his head. Mason then told the Sheriff the defendant was left handed and could not have swung the cane, hitting the victim on the left side of his head. This is not correct as many people do multiple things with their non-dominate hand (e.g. bat, catch & throw a ball, play pool, shovel snow, etc.).
When Ms. Blake is asking Perry the consequences of a guilty plea vs. a not-guilty plea, Perry explains that a jury could find her guilty or innocent. He should have said "not guilty" rather than "innocent." An attorney should know the distinction.