I’m not buying Hook’s act like he was caught in the heat of battle and barely survived. He totally heard about Snow and Co from Cora, so he snuck in there to pretend to be a survivor, to weasel into their group and piggyback on their ride to SB.
That’s what I’m thinking too…it may be why we see Emma pull a knife on him in one of the promos. Maybe she’s the first one to figure it out with her lie detecting super power.