Dustin Hoffman planned the moment when he throws his wine glass against the wall during the restaurant scene with Meryl Streep. The only person he warned in advance was the cameraman, to make sure that it got in the shot. Streep's shocked reaction was real, but she stayed in character long enough for writer and director Robert Benton to yell cut. In the documentary on the DVD, she recalls yelling at Hoffman as soon as the shot was over for scaring her so badly.
The final courtroom scene had one important rewrite: Joanna's explanation of why she left. Robert Benton feared major delays but, in fact, Meryl Streep had in mind what she wanted, and quickly rewrote the monologue. Benton said, "Well, the scene is brilliant. I cut only two lines. What you see there is hers."
Dustin Hoffman, who was going through a marital separation and who divorced his first wife soon after filming ended, contributed many personal moments and dialogue. Writer and director Robert Benton offered shared screenplay credit, but Hoffman turned it down.
The famous ice cream scene, where Billy challenges his father by skipping dinner and going straight for dessert, was completely improvised by Dustin Hoffman and Justin Henry. Writer and director Robert Benton liked the scene so much that he decided to keep it in the film.
When Justin Henry was nominated for the Best Actor in a Supporting Role Academy Award, Henry, at the age of eight, became the youngest person to be nominated for this award, as well as the youngest Oscar nominee in any category, a record which still stands today (2020).