At the beginning, Eli is sitting near a campfire. We can clearly see its flames, showing it is burning. When Eli stands up, the flames have disappeared, and we haven't see him extinguishing the fire.
Big Eli jumps into the muddy river from the top of the riverboat. In the next scene, he walks into the local tavern wearing the same "dude" suit and top hat, dry and unspoiled. (NOTE - That's because this sequence takes place that night, by which time his clothes would be dry).
When Big Eli and his son are in the boat, pulling up shellfish, Little Eli purports to pull a pearl out of the shell. Brother Zack gives Big Eli the opportunity of letting him fish for mussels.
A) Pearls come from oysters
B) The shellfish hanging from the ropes in the shot (26 minutes into the film) are clams, not mussels OR oysters.
Early in the film when Big Eli sounds the call on the large horn, you can see by his face that he is not actually playing the horn, This is confirmed when he removes the horn from his mouth and the last note plays for a split second longer.