I can't find anything about this online. I am not sure if an invalidly confirmed man would be a valid priest.
Good question. I'm sure it's required (or at least presumed to have been conferred) as a disciplinary matter, but whether it would actually invalidate his orders, not to have been validly confirmed (
ergo not confirmed at all), don't know, never gave it any thought. I'm not sure Ott or Denzinger address it. Anyone?