I've just been listening to a family member who is a reliable source.
Some nurses have been known to give blood to witnesses without them knowing, by putting pillows over the Blood bags.
Quite a common thing apparently.
Also my uncle, a social worker told a sad story of a little girl who needed blood but her beliefs meant her parents refused. Anyway it was taken to court and the girl was in the end given blood.
At the age of 12 she took her life because she felt dirty, unclean and felt she had no right to live.
WTF is wrong with the witnesses, doing that to a kid who has every right to be on this earth.