Maybe a bit off topic, but if it's any comfort, I checked it against some other functional languages with mutable state - Scheme and OCaml - and Scheme shows the same behavior (at least when used in this way, which I felt was most analogous to the Lua code.)
> (define recursive
(lambda (n)
(if (= 0 n)
void
(recursive (- n 1)))))
> (recursive 3)
#<procedure void>
> (define renamed recursive)
> (renamed 3)
#<procedure void>
> (define recursive void)
> (renamed 3)
[Repl(15)] Error: incorrect number of arguments to #<procedure void>.
Type (debug) to enter the debugger.
So as far as I can tell, there seem to be other successful functional languages that act this way.
