My mother was having surgery performed a few years ago and my idiot brother who was an elder at the time filled out her blood card and checked "no" for every elective blood fraction treatment because "Jehovah doesn't like blood."
The type of surgery she was having bore a very, very low risk of complication, so I decided not to blow up my relationship with my family over it, but I was incensed.
My brother had no idea what kind of danger he was unnecessarily placing my mother in just because he was too stupid and lazy to even comprehend his own religion's teaching on the subject.