Did Sai Baba really die? I'm confused about what happened to him.

The scripture clarifies that what we call 'death' is not what happened to Sai Baba. Chapter 43 explains that for a great Yogi like Sai Samarth, death is a trivial matter. He could die at will. The text states that both birth and death are false imaginations for one who is an incarnation of the divine, appearing for the welfare of devotees. When his work was done, Baba chose to merge himself into the unmanifest, but he continues to stay in the hearts of his devotees. The idea that his body 'perished' is rejected, as he who was imprinted in the hearts of devotees cannot be gone. He simply attained his previous unmanifest state and continues to protect his followers.