Did you confirm it was a single lion that did the killing? Just the killing and not feeding makes me lean towards a pair or two of juveniles. I would be interested to hear what others think. Especially @WAcoyotehunter @bearpaw and @Machias who have run hounds and seen a lot of lions.
It's not at all unusual for 1 lion to kill multiple sheep or goats. It's like turning a house cat loose on a family of mice, they can't stop, they will likely kill every mouse they see, same with sheep and goats and lions.
Is that more common to a younger cat honing his skills by killing like it's still a game?