The conclusions of the FBI on the handwriting seen in the photograph that they made from microfilm are minorly questionable, not highly questionable. They also made conclusions on original documents. Those conclusions are not questionable at all.
Tim,
Conclusions by experts are always questionable to some degree. In many cases the two sides will present their own experts who will provide completely contradictory conclusions about the same evidence.
That said, the conclusions they made on original documents were not the subject of this conversation. An expert can be a thousand times right on other original documents and still be wrong on a non-original. And besides, can you explain how an original signature on an original document can be authenticated to having been written by a now dead person?
And finally, whether you say that their conclusions about the Kleins' documents are "minorly" or "highly" questionable, you're only talking about the degree of questionability. In either case the bottom line is that those conclusions are in fact still questionable! Agreed?