When Barrie is rebuffing Peter for saying Porthos is just a dog, the stuffed toys behind Peter change orientation in relation to Peter at least twice.
When J.M. gets out of the car when they are on their way to the cottage to shoo off the sheep, the road is muddy with puddles all around. When he gets back in the car, the road is perfectly fine.
Barrie's dog "changes" between two dogs throughout the film. In the scene where Barrie dances with his dog, the dog he dances with has a tinge of ginger in his hair, whereas before the dog did not.
When Barrie is explaining the concept of the play to Frohman, there is a car approaching them from behind as they walk down the street. The position of the car changes dramatically between shots, though the continuity of the conversation is unchanged.
Barrie and his dog are playing fetch in the park, with Barrie using a fishing pole with a ball at the end of the line. As they walk on in the park, Barrie no longer has the pole. Later, when entertaining the children in the park, he has the pole again.
As with most factually-based movies, many people and incidents from J.M. Barrie's biography are conflated and rearranged for dramatic purposes.
How did J M Barrrie get an orchestra into the house without anyone knowing.
The first scene of "Finding Neverland", is set in 1903, the opening night of James Barrie's play "Little Mary". The vehicle in which Mr & Mrs Snow arrive is a Rolls-Royce model 40/50 HP, also known as a "Silver Ghost". This is an anachronism. The Rolls-Royce company was formed in 1904, with production of the 40/50 HP started in 1907. Moreover, the car has a "Flying Lady" mascot on the radiator which was not designed by Charles Sykes until 1911. The specific car is identifiable from its registration number - BM 8794. It is chassis number 1979, which was delivered new on 10th May 1912. The car used to drive to the summer cottage is a Mitchell Tourer, made in Racine Wisconsin, USA. Although the Mitchell-Lewis Motor Company was founded in 1903, the model in the film appears to be about 1911, judging by the shape and style of the lettering on the radiator. It's certainly no earlier than 1910.
When Barrie plays an 'Indian' and speaks with the child, from the back of his head, his motions do not match his words.
When Peter is knocking over his set for his play, a man in a t-shirt, blue jeans and a baseball cap is reflected in the window.