emacs-lisp-mode highlights incorrectly defmacros/defuns’ arglists

["Garreau\, Alexandre" <galex-713@galex-713.eu>]

At least *someone* must have *seen* this:
#+BEGIN_SRC elisp
(defmacro unless (cond &rest body)
  "If COND yields nil, do BODY, else return nil.
When COND yields nil, eval BODY forms sequentially and return
value of last one, or nil if there are none.

\(fn COND BODY...)"
  (declare (indent 1) (debug t))
  (cons 'if (cons cond (cons nil body))))
#+END_SRC

“cond” is highlighted in blue, while since defmacro (as well as defun,
which present the same issue) is itself a macro, and the meaning of its
arglist is known and fixed in lisp (a list of symbols, whose the first
isn’t particularly meant to be called), why is cond highlighted just as
if the arglist was a real form to be evaluated, while we know it’s not?

Wouldn’t there be a way to turn off these highlightings in such places
of known old and fixed macro calls?