So I was remembering in Season 4, when Emma told Killian that Regina was training her to use her magic. He replied that he knew she had powerful magic. “I saw what happened when Cora tried to take your heart,” he told her.
Just think about that a moment.
Where was he when Cora tried to take her heart?
He’d just finished swordfighting with Emma, and she clocked him with the compass, knocking him out. He was laying in an unconscious heap when Cora tried to take her heart. Or so we thought.
Apparently, he wasn’t laying there unconscious, as Emma – and Cora – presumed. He could have gotten up. He could have held his hook to Snow’s throat, or grabbed Emma from behind – in short, he could have continued to help Cora.
Instead, he lay there face-down in the sand, and deliberately let Emma get away. He rescued Aurora’s heart (and there was no need for him to do so), and then he let Emma get away.
There’s just nothing like a bad boy with a heart of gold.