I wish I knew more than what I offered, deegee. I don't think I could get those answers even from the exorcist however, though I am certain there is always work to attempt to ensure that natural conditions are not mistaken for something else.
I do know that those in the Catholic Church who deal with such things are themselves not afraid to say "we don't know." This I think can be very healing to hear for many of us who were once JWs.
Even after leaving the Watchtower we may spend years trying to find our own truth, but in so doing we might demand "truth" in a form that lives up to standards demanded by Jehovah's Witnesses. Most of these are unrealistic, even unreasonable.
Jehovah's Witnesses insultingly draw definitive parameters around concepts which are supposed to be spiritual and, as a consequence, transcendent. While religion for most is supposed to be a letting go to the great mysteries of life and embracing the mystery of it, Jehovah's Witnesses have reduced religion to a scholastic exercise teaching that something is not worth believing if one cannot explain it.
God, for instance, is for the most part completely "knowable" for Jehovah's Witnesses, with rules made up for God: God cannot be a Trinity, God has to have only one true religion on earth, God will only answer prayers if they contain an utterance of God's name, etc. The most mysterious things are reduced to puppets that more or less always act within rules as expected.
So a healthy asking for answers to such questions may be on the minds of everyone, non-JW as well as JW, but the acknowledgement that such details cannot always reasonably be expected in many cases might be telling of where else the Watchtower still remains in us and may have to be uprooted.
I guess this where an actual leap of faith comes in, not the type taught in Watchtower Land either. There comes a point where even doctors and priests must admit they don't know and just have to do their jobs. Sometimes it means the priest must turn away the "possessed" subject to doctors, and sometimes the doctor must turn away the patient to a priest. We are talking not hypotheticals but of desperate situations where lives hang in the balance. Sometimes you have to take a step into something you neither believe in or understand to save a life.