If a single lion is suppressing a sheep herd, it's not a viable population. It can certainly happen with transplant populations that are low in numbers and naïve to to the new habitat, and NM desert sheep herds are a great case study for such situations. We helped to remove offending lions to let those populations grow in NM, but once they were larger and established, they could handle the predation. The point is that the single lion that was removed was an indicator that the herd had other problems. The Spanish Peaks herd was probably suffering from what ails many wild sheep herd around the west. They are small, isolated populations that are more impacted by stochastic events such as as a bad winter, a pathogen spillover, or a single lion that acquires a taste for mutton.