That's what the 'experts' are saying, according to this article...

far from displaying highly unusual empathy with a human being, the lions were almost certainly preparing to eat or attack the girl when they were surprised by police searching for the missing youngster...

Colonel Lemma Legesse, a professional big game hunter, said the lions, having chased off the larger humans, were probably getting ready to devour the helpless girl, as they would any other prey, when they were interrupted.

Ketma Amberber, head of the zoological and natural history museum at Addis Ababa University, echoed that sentiment and offered another theory as well.   "This was just pure luck, it was not a question of guarding the girl or keeping her safe," he said. "Either the lions had already eaten and were full or the police arrived as they were deciding whether to eat her or attack."