Excuse me, but WHAT?!!!   I have MET people who KNEW Prabhupāda in the 1950s.   And several who knew him in the 60s and 70s.   Blood?!!!   I don't remember ever hearing about the need to consume BLOOD!   Kṣatriyas perhaps are allowed to consume meat, but brahmacārīs, gṛihasthas, or sannyāsīs?!   Absolutely NOT!   Only in a life or death situation should they do so.