Circling back to this:
I don’t know where you saw that fact being presented
It's not something I read yesterday, but something I've encountered upon most life scenarios, upon all my readings and personal experience over the years. So again-- it's absolutely true in general, far as I know.
Indeed, right in the article you linked, reasons and causes were specifically mentioned, so it wasn't really a case of pointing killing, far as I know.
That said, I do suspect that a predator's instincts to kill can indeed go on 'automatic' at times. Easy enough to see in domestic cats upon zillions of examples, but I think it can also be argued that keeping one's predatory skills sharp is generally super-important for predators. A little but like how given the opportunity, we naked apes love to spend loads of time on flying, killing, driving simulations, etc.
So, far as I know? What I said originally still commonly holds, with some caveats.