Can someone help me with how Walker is dead?

I saw the interview but its still confusing because both Walker and Adams were in the helo but they die sepreatly from each other when Walker was reliving Dubai. And how did he relive the epilouge if he was already dead before that could even happen? Cuz all that I can think of is that hes being judged and if he surrender to falcon one he goes to heaven and if he fights he goes to hell. So anyone know the real answer cuz im real confused?