It is not really just a plot hole. He just didn’t think Captain Hook could do anything to him. No offense to Captain Hoom fans, but he was not all that formidable. He has been bested numerous times by Emma and Belle. Not once has there been any real threat–not until he managed to push Belle over the line.
And Rumpelstiltskin was able to beat him up pretty easily. He was confident that Captain Hook could do nothing to hurt him.
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