When Wilde's butler brings him the newspaper with the news of the death of Bosie's brother, he whispers to Wilde "Back page, sir," but Wilde turns to an inside page.
When Oscar Wilde visits his wife's grave near Genoa, the headstone states "Wife of Oscar Wilde." It originally stated only "Constance Mary, daughter of Horace Lloyd, Q.C." and "Wife of Oscar Wilde" was not added until later.
In the court scenes, the judge is wearing a full bottom wig. This practice died out in the 18th century and in Wilde's day (as today) judges wore short wigs known as undress wigs.
When Oscar is walking through Kensington Gardens, London, (seen as a wooded park) with his wife Constance and their baby in a pram, a part of the sculpture "Physical Energy" was in view. This sculpture of a horse and rider was erected in 1907, however Oscar died in 1900, so this was not possible.
When Bosie enters Oscar's room in the country house, a picture to the left of the door reflects a studio light and later, when Bosie sits down, the boom.