I know this doesn't help the folks in prison without any resources, but during a trial, can't a defendant ask for any DNA test to be rerun by a private lab at their expense?
But the defendant themselves paid one of the experts, so...
I do not know with what regard, under US jurisdictions, the evidence provided by "expert" witnesses is treated, but at the time, we were told by the presiding judge to treat it as opinion by an "expert" and not as direct evidence.