Several years ago we read of a girl who was apparently threatened by humans being protected by lions who chases off the males and stayed with the girl. Explanations like, "her crying resembled that of a cub" etc. were invoked.
Why is it so hard to believe that adult lions who almost certainly know the difference between a lion cub and a human could not have been acting altruistically as they sometimes apparently do with, for example, prey animals that they sometimes encounter? If a domesticated dog or cat protects a human, we accept that they know what they are doing, do not confuse the human with their own young. Lions are plausibly more intelligent than a dog or cat or at least within the dog/cat range.