Thomas, indeed, aloha.
while waiting for authoritative information, i'll notice that the
Makefile calls an elisp function
----
(defun org-make-manuals ()
"Generate the Texinfo files out of Org manuals."
(require 'ox-texinfo)
(dolist (manual '("../doc/org-manual.org" "../doc/org-guide.org"))
(find-file manual)
(org-texinfo-export-to-texinfo)))
----
and, (org-texinfo-export-to-texinfo) (in ox-texinfo.el) seems a
fully-functioning export module, and i don't see any reference to pandoc
in it. (but, i've never looked at that code before.)
cheers, Greg