The information is only as good as the source: death certificate, tombstone, Will & Probate, etc.
DAR tightened up on proofs before SAR but both could be incorrect. A transcription error is only one type of error. You would need to look at original DAR & SAR applications and see if proof was even submitted.
Hereditary Society application papers, like unsourced online trees are just a 'clue.' A lot depends on WHEN the paper was submitted. That can be deduced from the application number but that is not a certain criteria. When I say it not only depends on when but who verified it and, yes, the phase of the moon (physical and political.)
DAR's online abstracts are just that - transcriptions from some paper, approved at some time with varying degrees of proofs.
DAR does try to make corrections but, remember its goal is to get members.
The DAR Library has a weath of genealogical information. It took me over ten years to learn and locate most of the records. There are also private application files, which are used by the genealogists and not available to the public.