Yes his transformation was complete. And he- she was happy or at least ready to hunt. There was just one thing that you (yes YOU) forgot. Why was the backyard door locked. Right before Jeff "died" he didn't stop to consider who locked it.
Of course it was someone who did it, possessed by the same thing that everyone on this website is possessed by. Curiosity, why else would his father let him die? But after looking through the window once it was all done with, he realized something. How would they live now that his son and wife are beasts, he couldn't let them run wild in the forest- they could die or even get captured by groups with their own agendas. But if he let them stay; how would they live? And so he just went into the living room trying to relax with the two monsters in his backyard, not knowing that the Chronivac had shut off setting changes to permanent, all by itself.