Of course, Jack did not know about what Sebastian had done. But even if he came to know about that, he was not going to care much about it. In any case, it was not as if the people from Derek's family were not going to know about the fact that he was the one who was involved in the killing of the two, Derek and his guardian.
At the end of the day, Jack had not even tried to hide the fact that he had killed the two of them. And to say the truth, although he really did not want trouble, it was not as if he was the one who went ahead and looked for them.
Instead, it was Derek who came out of the stronghold domain, to the normal world, just to look for Celine. And after that, he began causing trouble for the two of them. Then, targeted Celine, something that was completely above the limit that he could tolerate.
