Continuity mistake: At the very end when the Nicklebys are confronting their Uncle Ralph, at one point Ralph slumps down over his desk. He's off screen and you hear the thud of him falling, but the eyelines of the people on-screen don't change a bit; they continue looking slightly upward. You'd think if he was falling over they'd follow him down with their eyes and they'd move at least a little.
Continuity mistake: When Smike and Nicholas are with the theater company the man who is the savage is just about to perform the highland fling Mr. Crummell comes up and stops him. The man who is the savage in the play grabs the flams then in the next shot they show him grabbing it again.