Tom and Huck (1995)

Continuity mistake: Tom and Huck have just swore they won't tell about the murder. Tom writes an oath, and Tom and Huck slit their fingers to sign it in blood. Tom, slits the index finger on his right hand. He signs the oath, however, with his index finger on his LEFT hand.

Tom Sawyer: Muff's innocent Huck, we gotta help him.
Huck Finn: We ain't gotta do nothing.
Tom Sawyer: You'd let him hang for something he didn't do.
Huck Finn: It ain't no skin off my back.