The Tibetan Book of the Dead is a pretty intriguing text on the topic, but I do take it with a grain of salt. It's a template, a starting point, but it is a culturally-b(i)ased work. It should be liberally interpreted by others and the general concepts that can be gleaned from it are more important than the actual text, I think.
One thing from the "Old Souls" book that stood in contrast with the Tibetan Book of the Dead was the time scales involved, and I've never been comfortable with the time scales in the Tibetan Book of the Dead. Too concrete, too normative, grounded in our subjective reality. I'm concluding that is one of the things that should be interpreted liberally.
I don't think time is an objective, normative phenomena of the universe. I agree with Einstein that time and space are inseparable, and once we don't exist physically in space, neither do we exist in time as we know it.
Time is our fishbowl. We don't have the mental architecture nor the imagination to envision the non-existence of time. If time was created by the Big Bang, when did the Big Bang occur? We can't even approach that concept since time is so hard-wired into our very existence.
So for people who read the Tibetan Book of the Dead and are intrigued and find some belief in reincarnation, we can formulate our own ideas of what happens and how and why, but not when. So when my cousin says that her infant daughter had mentioned she was her mother in her previous life, who had died some 15 years earlier and thus beyond the bounds of the Tibetan Book of the Dead, I have nothing to say about that. My cousin's instant acceptance of her daughter's statement is no longer completely outlandish.
Ghosts are another issue that have recently been brought to mind. I'm open to the possibility that just as in "Old Souls", a death can be so sudden and violent that actual memory can be transferred into a next life, but that a life and death could be so filled with anger and attachment and/or fear that the phenomena of what we call "ghosts" occur.
A ghost phenomena may occur when there's a death but the circumstances prevent the natural progression towards rebirth and the energy gets "stuck" in its previous existence and can't move on. And again, time is irrelevant. A ghost existence can last for quite a long period in our normative understanding of time, but for a ghost, time is not a concept.
As I continue to read "The Lovely Bones", the murdered girl continues to watch what happens for years and years after her death. I'm reading at the point where she's watching her younger sister's college graduation, and to me, it seems that it's not like she's sitting in heaven watching in real time what happens 2, 5, 8 years after her death; that in heaven, it is actually 8 years after she was murdered.
But in her death experience, she watches what happens after her death, far into the "future", but not occurring "in time" at all. So if I were to hypothetically plug her case into the template of the Tibetan Book of the Dead, she could witness all the things she reports as being far in the future, but it has no bearing on when her time in the bardo states ends and when the natural sequence of events pushes her into a reincarnated existence.
She narrates events years and years after her death, but in our normative time line, she may have already been reincarnated when those events actually occur.