Well, with the header on each page of  "Case 1:20-cv-04651-SDG   Document 6-14" it should be easy enough for a lawfag to verify its authenticity. I'm going to take it as an invitation to practice discernment of TRUTH. To do that, I will concentrate on validating the TRUTH of the text that I can read. So, you rightly point out to verify authenticity of the document itself.  Then verify the content of th doc.  Then verify the submitter of the doc.