War Horse, the app

Ik heb het boek (nog) niet gelezen en heb geen iPad, maar vind het wel fascinerend:

The app features a specially filmed performance of War Horse by author Michael Morpurgo, accompanied by musicians John Tams and Barry Coope. It also features interviews with Michael Morpurgo filmed by award-winning arts media company Illuminations in Iddesleigh (Devon), where the novel begins and ends; historians discussing the First World War from the battlefields of the Western Front; the National Army and National World War I museums; and more.
In addition to the abridged text used for the performance, the original book’s full text is included alongside a full audio reading, context-sensitive notes, period documents and artefacts, allowing the reader to delve into the historical background of the story.

In hoeverre leidt al die aanvullende informatie af van het echte verhaal?