[xtracto]

The article doesn't mention it but the researchers are using agent-based-modelling. It was nice to see the gif of what appears to be either NetLogo or Repast. I did research in that area for about 8 years and know a bit about the subject.

What they are showing is one of the main issues with agent-based-models (and I think every model, but it happens particularly with models trying to capture the behaviour of complex open systems): Garbage in -> Garbage Out.

Most likely the representation of the sheep/wolf system was not correct (so the modeling was not correct). Here "correct" means good enough to demonstrate whatever emerging behaviour they are studying. ABM is a powerful tool, but you must know how to use it.