Question: In Nick's case, why is nothing shown happening to Jackie at the end? I mean, if it wasn't for her kicking out Chase and Andy, so that she could have the house party (while her parents are on vacation), they wouldn't have ended up at the laundromat where Chase dies.
Answer: There are not enough jail cells or funding for them to waste time and money charging people for crimes who are an indirect puzzle piece as opposed to being the person who directly committed the crime. While Nick is not a cop, he knows enough about solving crimes to know the law comes down to who is directly responsible. The law doesn't put much focus on who you could put some of the blame on indirectly, hypothetically speaking. No one in law enforcement is going to waste their resources charging Jackie. Particularly when all her lawyers would need to say is, by law, she didn't commit a crime.
Answer: What is often called bone marrow transplants is the transplant of hematopoietic stem cell. Instead of blood type match, patients need to be an HLA match (human leukocyte antigen). There's a lower percentage of matching one's HLA type with a random person than blood type. When it comes to matching human HLA types, a person's ethnic background is important in finding a match because the HLA markers used in matching are inherited, and some ethnic groups have more complex tissue types than others. A person's best chance of finding a donor may be with someone of the same ethnic background, meaning someone on the registry would have to be of mixed race as well. At the time, the total number of multiple race donors in the registry was very low (I don't have the figures for 2004, but in 2014 there were less than 500,000 multiple race donors).
Bishop73