I understand that it's not the only sample, etc.
It has to do with the fact that LE told the public too much.
GEDmatch is now decrying the whole thing as " unauthorized use".
What this could do, and I hope it doesn't, is open the door to doubt of the integrity of the case in total. Evidence, specifically and the legal chain of custody.
Because to the best of my knowledge, what they did was innovative and savvy but I don't know if there are any laws about this type of DNA familial matching, especially in CA, the most liberal state in the US for individual rights of a criminal.
Remember in the O.J. Simpson trial, things started to go south for the prosecution when Mark Fuhrman's racial slur which had been taped 10 years prior was played in court. He had said he didn't use racial slur words, then they played the tape.
After that, ALL of the blood evidence was questioned because he had collected some of it.
The bloody glove was called into question because he had bagged it. Blood evidence on the glove was said to be not valid because the defense found a gap in the legal chain of custody in one of Fuhrman's samples in the lab. Not that Mark didn't maintain legal chain of custody, but that a lab worker failed to initial, date, and log in one specimen he collected.
IMO, in the state of CA ( and FL), if there is any doubt about the handling of evidence, or if the jury does not understand what has been done and why, the case is going to be very hard to win.
We've lived through it with OJ, and in FL, with Casey Anthony, because that jury totally did not understand the forensic testimony. Not one word of it.
You get stupid juros sometimes. I know why LE did what they did at GEDMatch but the jury may not.
A jury only knows who's saying " Objection, your honor" at every turn sometimes.