The boat falling off of the waterfall would never have caused a fire.
When one of the shinobazu made the tributary for the bottom half of the boat to travel down, he tunneled it into a cliff face, but in this episode, the boat does not go into the tunnel, but off a waterfall?
The snake that obstructs the way of Naruto's three man party is, in reality, not poisionous at all. It is a king snake, often confused with the actually deadly corral snake. As the rhyme says: "Red touches black, (referring to the stripes) venom lack. Red touches yellow, kill a fellow".
When Todoroki is telling Naruto they should kill Gantetsu before the Shinobazu get him, we see him from behind. If you look at his left side, the sheath for his sword is nowhere to be seen.
(The Shinobazu are closing in on them quickly)
Naruto: Here they come again. We gotta run! Hey, we gotta get moving.
Todoroki: I won't allow him to escape. The safest thing is to finish him off right here.
Naruto: What are you up to? What the heck do you mean finish him off?
Todoroki: He's certain to be found guilty and sentenced to death anyway. We can save them the trouble. Better that than to let his friends rescue him!
Naruto: Take it easy! They haven't rescued him yet! Let's go! (Naruto grabs Gantetsu's arm and starts to run) Your mission is the same as mine. We're supposed to guard him, not be his judge and executioner!
Shura: My jutsu isn't ninjutsu, it's a murder jutsu.
Shura: All right, kid. You'd better get out of there or you're gonna get hurt.
Naruto: I'm no kid and if you think we're handing him over to you, you're crazy.
(Lee Struggling to stay above the surface)
(Sakura jumps out of water and uses her chakra to run on top it to drag Lee to shore)
Sakura: Lee-san, are you okay?
Lee: Yeah, amazingly enough. More importantly, where is Naruto-kun?
YTV Airdate: October 24th, 2009
Original Episode Title: Labyrinth Forest
Original Airdate: November 16, 2006
The reason that Sakura had to save Lee from drowning was because Lee cannot use chakra control on his feet to walk on water, since he is a taijutsu user only.
Gantetsu is willing to lead Naruto and Todoroki out of the forest instead of leading the two of them to their deaths.
The Shinobazu are not looking to get Gantetsu back. Instead they are trying to capture him to get back what he stole from them.
According to Todoroki, and his memories, Gantetsu was responsible for the death of his entire family. That is the reason Todoroki wants to kill Gantetsu so much.
Gantetsu claims to be an enemy of the other shinobazu. He says that he stole from them, and all they want is their money back.
The forest that the shinobazu reside in can only be escaped with one of the shinobazu as a guide, because the forest screws up a shinobi's sense of direction.