In the Book
In the Movie
A police spy known as Le Cabuc shoots down a man looking out of a window near the barricade, and is executed by Enjolras.
A nameless National Guardsman shoots down an innocent woman at Lamarque's funeral, sparking the revolt.
Courfeyrac is knocked down during the first attack at the barricade, but Marius helps him recompose himself quickly enough to survive.
This happens to Courfeyrac at Lamarque's funeral, and it is Javert who helps him up.
Gavroche meets Valjean outside the Rue de l'Homme Armé to deliver Marius's message.
Gavroche meets him in the stairwell inside the bulding.
Valjean shows up at the barricade during a dispute over five men who wish to leave the barricade with only four National Guard uniforms available, offering his own as a fifth.
Valjean shows up claiming to be a volunteer, and is threatened by the revolutionaries until Gavroche vindicates him.
Valjean is allowed to take care of Javert because of his silent contributions to the barricade.
Valjean helps shoot down a team of enemy snipers, which is why he is allowed to deal with Javert.