There were two different laws on blood the one given to all mankind and that given to the Nation of Israel.
At Duet. 14:21 it states "You must not eat any body [already] dead. To the alien resident you may give it, and he must eat it; or there may be a selling of it to a foreigner." There in Israel’s mist was the man of the nations,
this foreigner represented the rest of mankind that Jehovah gave the command to at Gen: 9:4.
at Lev. 17:15 read "As for any soul that eats a body [already] dead or something torn by a wild beast, whether a native or a alien resident, he must in that case wash his garments and bathe in water and be unclean until evening; and he must be clean." Here God say’s even the NATIVE could eat an animal that he personally did not kill and he knew that this animal had not been bled, and not be in violation of god’s law on blood. {A native, is a person that was clearly under the Mosaic Law and bound by it} How can this be?
Here it states a native{person under the Mosaic Law} could eat an animal not bled and not be put to death. Why? His only sin is one of touching a dead animal and then he became unclean. He did not violate God’s law on blood here or Jehovah would have put the sinner to death. His only sin here was one of touching a dead animal. {The Law’s requirement for touching a dead animal is he became unclean by the act of touching a dead body}. Since he touched a dead body he was unclean until evening and he had to wash in water. At Lev. 17:15 Think about this example, Jehovah gave Israel away out of death. If there was a famine in the land or drought… and one happened upon a dead animal, the eating of that animal could literally have meant saving the life of that person and his family.