Continuity mistake: Enjolras is holding a book during his protest which disappears and reappears at will.
Continuity mistake: After Eponine dies in Marius' arms, Enjolras and Combeferre lift up her body. Enjolras' position changes from right to left.
Continuity mistake: At the start of "One Day More", Eponine is holding Cosette's letter to Marius. It is crumpled and wet in close up but brand new and dry in the wide shot.
Continuity mistake: When Enjolras is shot dead, he falls out of the window while holding a red flag with both hands. When he gets hung up, he's holding the flag with just one hand.