Your question comes from the perspective that sleep paralysis includes an hallucinated experience. An experience that did not really happen. Whereas my perspective is that sleep paralysis is a real lived experience, albeit in another dimension that we can not articulate, explain or rationalise at the moment.
I am clear in my knowing that the experiences take place whilst my body is in its ethereal state and that this happens to millions of people all over the world each night. The basis for this is that we are fundamentally spirit within a human body and that as we sleep we have ethereal experiences.