LISA
I watch everything unfolding before my eyes and there is no doubt in my mind that this man is indeed his dad. They act the same and they look the same. I see them agreeing with each other on a nonverbal level and all the psychological signs are there. They are related as you can see it easily when you study them close enough.
I worked for a year in treating children that lost their families and reuniting them again. I can see when they are related and I have never misdiagnosed one of those cases. This, what is happening before my eyes, is one of those cases but then I see the leader blowing his top and shooting Brian in the shoulder.