Subpart J--Records and Reports
Sec. 211.180 General requirements.
(d) Records required under this part may be retained either as original records or as true copies such as photocopies, microfilm, microfiche, or other accurate reproductions of the original records. Where reduction techniques, such as microfilming, are used, suitable reader and photocopying equipment shall be readily available
He points to the above, stating the regs reguire "true copies" or other "accurate reproductions of the original records". He stated that it is the FDA expectation that if you discard the original (which would be your evidence that the copy is accurate and complete) there must be some other evidence that the firm has an accurate reproduction of the original. Thus, he recommends (certainly NOT a reg, but his recommendation on how to provide such evidence) - the review of the original against the copy with the certification that it is accurate and complete.
I personnally have had instances where a scan copy cut off words on the edges, and even missed a page during the scan.