OP: Thanks, Randy! FFIEC confirmed that the link I am asking about (
https://www.ffiec.gov/bsa_aml_infobase/documents/red_flags/Money_Instru.pdf) is an older link that was replaced by Appendix F of the current version of the infobase, in 2014. (I believe it may have been replaced in the 2010 or 2011 updates, but 2014 is fine for my purposes here today.)
As near as I can determine, there is no series of clicks from Google or anywhere else that would lead me to that page from 2005 or whenever. It is not valid any more, because it was replaced. That's the stance I'll be taking.
The FFIEC could not explain to me how anyone could have navigated to that link without either a) knowing the URL somehow or b) having it cached or c) having it bookmarked.