They are comparing apples amd oranges. Your liver removes alcohol from your digestive tract sending it to your bloodstream, so the effect of alcohol is the same whether you transfuse it or drink it, but blood that is transfused is never utilized by the body for food. You could get a blood transfusion every day and still starve to death if you did not eat. So you are not eating blood when you get a transfusion.
But a better argument against the ban on blood transfusion is that it is clear from the bible that it was the symbolic bleeding of an animal that was the reason blood was not eaten, it was to show respect for life. Otherwise, if eating blood was in of itself wrong, they really would not be able to eat meat at all, because it is impossible to drain all blood from an animal, there are always trace amounts left over along with other fluids, as you can see when you cook a steak.
Another angle to consider is that Jesus performed healing on the Sabbath, something forbidden by mosaic law. He obviously believed that saving a life was more important than blindly following a law. So why would we throw away a human life for something that was a sin under mosaic law? How is that showing respect for life? Yes, the apostles admonished others to abstain from blood, but was that because blood is of itself bad, or because that was the custom of the that time, since most early Christians were originally Jewish?
The Watchtower knows very well there is no reason to ban transfusions. They started this when blood transfusions were new and more risky, it was based more on ignorance and fear of modern medicine than any real biblical reason. Now they can't admit they are wrong, since they have bragged so much about all those who threw their life away by refusing a transfusion, everyone would realise they died for no reason. That is why they started allowing fractions, it gives them an out. But if blood is inherently bad, why is using even part of it OK? You are still taking whole blood from someone, taking out some of it and using the rest. What makes that any different than whole blood from a religious standpoint? Did the mosaic law say you can bleed an animal, separate the components, throw some away and eat the rest?
