Spoilers for sure (don't read if you haven't seen the film)
I didn't like the reference to military testing of BZ, because it introduces a big flaw in the the story. The fact is he could never have known he was actually drugged, if in deed he ever was, since everything we see in this film is purely the product of his mind (except presumably the scenes in Asia and those scenes with his son Gabe that may be flashbacks). He is bayonetted and dying, sensing the existential threat, his mind wanders through a maze of paranoid delusion. He does the human thing, which is to recognise patterns in what is essentially just random noise, and invents conspiracy and persecution both very material straws at which his mind grasps desperately trying to make sense of what is senseless - his pointless death due to mistaken identity. Then again maybe he didn't die at all, at least not literally. Maybe the film is about a man on the verge of complete mental collapse after suffering prolonged post-traumatic stress disorder who can no longer separate past from present and develops extreme paranoia. In both case, the BZ reference just annoys me.
some other thoughts:
In the Bible, Jacob's Ladder exists only within a dream. It is seen as a metaphor for the human soul, which is a conduit for angels: here Jacob's ladder is his schizophrenic and/or imaginary post 'Nam life populated by demons. The drug and the chemist are figments of his imagination.