Thanks for finding that letter. As DPE's we were told to not specifically endorse for a flight review from a CFI ride because that would require the DPE to provide at least 1 hour of ground instruction and 1 hour of flight instruction and that would be in conflict with the idea of no instruction to be given on a practical test. That's why we were told to write, "All pilot operations checked."Just got an email from another DPE friend with this link from the FAA legal regarding this issue.
I humbly admit I was wrong.