the medical bay cutscene at motherbase hurt me
drag over for spoilers
you find paz in the med bay, as it turns out she survived the fall into the ocean, as both the bombs were removed. The cause of the explosion was due to a rocket launcher hitting the helicopter from a helicopter to the side. But due to the explosion, the shock, and the near death experince, paz has complete amnesia and still thinks shes stuck in the 1970s.
Goddamnit Kojima, this was all optional to find as well, I wouldn't of even seen it if I hadn't decided to explore the medbay.