Black Snake Moan (2006)

Continuity mistake: At the beginning, when Ronnie leaves Rae, her shirt changes position on her left shoulder. The positions change back and forth between the shots.

Lazarus: I remember my first time, it was out behind my uncle's barn with my second cousin.
Lazarus: She was two tons if she weighed a pound, I could have done better for myself.

Question: What is the significance of Rae repeating what Lazarus's ex wife said at the beginning of the film, "See if I give a s**t about all you people"? Is this to suggest that the two met or what? I don't get it. Could someone explain it to me?