All joking aside, the hair testing is not sophisticated enough to know 'blood lines" as anything more than a bit of a guess.
I mean - blonde hairs are unlikely to be those of Maori woman, so its easy to say that therefore it is "250,000 times more likely that the hair was Olivia's than the Maori lady". And yeah, Ok, before any smart alec says anything, no that is not a verbatim quote from the case files, it is just an paraphrasing of something similar that the forensic hair lab lady said at the trial - if you want to know her exact words, go read Keith Hunters book.
The jury were basic