I posted this theory in another thread, but I’ll repost it here because of its possible relevance. Maybe Aurora could have sent a message to Hook. She knows him and believes he cares for Emma. Plus, Aurora and Philip seem to be “in the know” about the Wicked Witch. They could have easily tipped off Hook just before Zelena cast the curse.
I think this might be spot on.
We know Aurora has some guilt over not telling Snowing about the WW in the castle. She has a good heart and I think it’s going to get to her. So the question becomes, well how did Philora get a message to Hook? In the story of sleeping Beauty, Aurora has three fairy godmothers. This is where it gets spoilery
we know Sarah Bolger was back on set for 319, also where we meet…GLINDA!!! I think Aurora gave Glinda the message and she delivered it to Hook