every superior predator ever in history is dead. because of humans. we made dozens of species that would absolutely and totally dominate all modern wildlife, go extinct. from bears that make modern bears look cuddly, to wolves that make modern wolves like chihuahua's, to birds that make modern birds look like specs of dust.The animal was intelligent, and recognised that they were also intelligent because of the fire. That's why it let them go.
we killed them all. why would the predator out of the good of his heart, let us go. for what sane reason? the only sane thing for the creature to do was kill and attack, since we -being intelligent- are a humongous threat to it.
like i said, if the creature is intelligent, it raises plotholes, and if it's not intelligent,it raises plotholes.
even intelligent animals that saved humans, like dolphins, only ever helped us because they didn't loose anything. Dolphins are known to display empathy. they help humans to fight off sharks/orca's. but from a natural POV, this makes sense. by denying their natural opponent their food, they can live in a safer world.
but this predator allowed outright competition. we were hunting on it's ground. we stood in it's cave. no creature no matter how.. intelligent... will tolerate that.
we won't even tolerate it ourselves!