IMHO, any time a carnivore stands and looks unafraid at a human, he's a threat or will be in the future. If he's not afraid, the next step is "that thing looks edible, I think I'll try a bite."
The acclimation by animals to the presence of humans and said humans having no adverse effect on them is the reason for the increase of bear/lion attacks here in CO, and a DOW rep has said so.