There is no such thing as "Tighar's recent DNA claim." They have "claimed" nothing. Gillespie has simply said that they will return to Nikimaroru armed with serious advice on how to retrieve DNA samples without contaminating them, and will attempt to find an object of some sort that would have been handled by its "owner" and will compare DNA thus harvested to that of an acknowledged Earhart-family descendant.
I'm sure Ric Gillespie would admit that the DNA for all he knows will turn out to match that of Judge Crater.
Hard to respect the rest of what J5 writes if he gets this so wrong.