This is Windows specific, right?

From a quick google is not clear that CONOUT$ *should* point 1, since it supposed to get at the console regardless of whether there has been any redirection.  Certainly, relying on it doing so would seem to be problematic.  What does PERL return if stdout is redirected, and where does the output go in that case?

The io module does not use the c IO library, unlike the default open in python2 (the io module is the default in python3), so the behavior may also be different in the two cases.