As mentioned on the main page, Jason Took a Level in Jerkass, and, early on in Turbo, seemed to have some anger issues against Tommy. It's likely that, deep down, Jason wasn't entirely happy that Tommy took his role as leader, leading to some resentment.
It gets evenbetter. Another Word of God says that Turtle Cove was in Oregon; this Troper assumes it would be somewhere near Portland. Given that, it would have taken Cole a long time to make it from the jungle.
How did Cole's motorcycle beat Serpentera? Serpentera was shown to be capable of total planetary annihilation, and he flew right into its primary weapon?
Word of God is that the motorcycle counts as a "Holy Weapon" since it came from Animus. Yeah, I'm not really happy about that whole thing... My personal opinion is that they found a prototype of Serpentera, and THAT was what was destroyed.