Board Thread:General Discussion/@comment-70.27.62.150-20131011194647/@comment-3387274-20140303202342

a creature that defends it's nest would not persue those that invaded it halfway accross the woods, and would give up very quickly. The Deathstalker outright chased Pyrha, who was running away. It also attacked Ruby, who admitedly shot at it, but didn't even make it flinch, an Nora, who was busy with the Nevermore and didn't even see it till it was about to hit her. This is assuming it still holds a grudge against Pyrha and Juane as well.

Also, the Nevermore shot at Nora and Ren for no good reason.

Whatever your justification, Every single Grimm with seen attacks humans on sight, and in most cases continues to follow any humans even when animal behaviour wouldn't justify that.