While it's doubtlessly not very safe and probably unethical, a lot of people keep tigers as pets and they usually don't get eaten. If you gave a sabre tooth kitten to somebody experienced with raising large cats, my bet is they could do it without getting eaten. Probably. Despite the risk I bet you'd have no shortage of volunteers willing to try.
Unethical if done intentionally, only ethical if it's a rescue situation that cannot be otherwise avoided, everyone gets along well, and the particular cat isn't an absurdly-large lion or tiger.