I was barely a teenager in the late 60's, but I clearly remember reading that Watchtower QFR equating transplants to cannibalism and thinking they were nuts. I never agreed with their ridiculous position. As I remember, accepting a transplant would have been considered the same as accepting a blood transfusion. Unless a person "repented" and had some excuse such as yielding to pressure or fear in the heat of the moment, they would have been disfellowshipped. That said, I don't recall the issue ever actually arising in my small town.
The same with the nonsense they came out with in the 70's about the literal heart being the seat of motivation. Even I, with no medical education or training whatsoever, instinctively knew that was BS. I remember seeing that giant heart light up during talks at the District Convention and thinking how loony they were. I never believed that crap for a minute. I remember talking about it with my elder dad, and him saying that if it was wrong it would be corrected in Jehovah's due time. Otherwise, I just kept my thoughts to myself. I "knew" they were right about so many other things that I pushed this anomaly into the background. I didn't know what cognitive dissonance was, but I sure had it.
Even now, though they have abandoned much of the egregious medical quackery spewed by the Golden Age, they continue to impose their groundless religious interpretations on their followers' most personal medical decisions. They rail against in-vitro fertilization (IVF), egg and sperm donation, surrogacy, etc., equating it with adultery. This completely ignores the principle of brother-in-law marriage, which was not only allowed but sometimes required back in the good ol' "Bible days." It seems they can't understand that adultery is unfaithfulness and disloyalty to one's mate, and has nothing to do with the actual biological material exchanged. There is nothing special or sacred about any individual's sperm or egg cells in and of themselves. When assisted reproduction, whatever the exact method, is used to produce a longed for child, with the knowledge and consent of all involved, it is a gift of love. It has nothing at all to do with adultery. Only narrow-minded religious control freaks would equate the two.
This is just some of the evil that comes from self-appointed religious leaders applying their uneducated and ignorant lay person interpretations to scattered passages in a book of Bronze Age myths and superstitions and demanding their followers accept them as laws of God. This fallacious practice has cost many lives.