As a former member of that, um, organization, let me say that scientologists believe in reincarnation (not called that, but they do believe that we all come back in a fresh new body). Doubtless he believed he was giving Terri a chance at a new and healthy body instead of being imprisoned in a damaged one for decades and that this was an act of kindness, not brutality.
He was wrong, but he acted based on his beliefs.
So I have to ask. Have you met Tom Cruise?