Since this is related, I guess I should share a theory of mine that I already told RG. It involves spoilers, though:
For those who follow spoilers, we know that Isaac was announced to be returning around the time they were filming 617. I kept trying to think why they would need to bring Isaac back, especially since he was absent from “Page 23”, the most logical episode he could have played a role in. And then it hit me. I recall Adam and Eddy saying that the Papa Charming murder subplot would be resolved by Easter, and 617 happens to be the episode that airs on Easter Sunday. While of course 617 is expected to be when Snow and Charming finally break their sleeping curse, it could also serve as a resolution for the PapaCharming subplot. So how would Isaac factor into this? Well perhaps it’ll turn out that Hook only killed Robert because Isaac wrote him to do so to “make for a better story”. If it’s revealed that Isaac, rather than Hook, is responsible, then that makes it all the more believable for Charming to forgive Hook. It would be a cop out and convoluted for sure, but just think about which writers we’re dealing with here. They wanted their drama by making Hook the murderer, but they also might want an easy way out of resolving this. Of course this wouldn’t erase that Hook still withheld the truth from both Emma and Charming, whether Isaac controlled his actions or not.