Lets keep some basic things in mind about mtDNA testing, as people get confused, and there is far too much dis-information out there. mtDNA does two things: It establishes non-familial relationships between individuals with 100% accuracy. mtDNA mutates within a family VERY rarely, at least no often than one gene marker in ten generations, and most scientists believe closer to 20 generations. Regardless, a mis-match means "you're out". Period.
The ONLY possible way for a bad test is a bad sample. Period.
The second thing mtDNA can do is say ONLY that there IS a maternal familial relationship, but it can not say exactly how far back.
Now the original mtDNA testing done on the Anna Manahan sample was done with fewer genetic markers than today. (six vs. twenty). Now, is today's test more "accurate", sure. BUT and this is the BIG BUT (no jokes please...

) does today more precise accuracy make the earlier tests UNRELIABLE. ABSOLUTELY NO.
There were FIVE mis-matched markers between AA and the known Victoria maternal mtDNA line. A 20 point test would only show MORE mis-matches, and not less. The original mis-matches remain and will always remain no matter how more accurate the tests may become, the original test are STILL ACCURATE to determine an exclusion. The ONLY new result from the 20 point test would be to determine with greater accuracy (than the 98% probability of the original) that AA was related to FS. PERIOD.
THERE REMAINS TO THIS DAY NO SCIENTIFIC REASON TO RESTEST TO DETERMINE IF AA WAS AN. THIS is the point I keep harping on, because no scientist in the field has ever shown that the original tests are inaccurate, the exclusion factor remains, it is only for the "inclusion" factor that todays tests are better.
Think of it this way, my first computer back in 1987 was a 186 AST with the then astounding 500 meg hard drive...Now I use a 500 Mac G4 with a 120 GIG hard drive. Is today's new compter better, sure, but was my old computer useless and unreliable? Nope...the advances of today dont
diminish previous technology...they just make it better, the same is true with the mtDNA testing.