I don't see the controversy in stating the obvious - Howe is not an infallible manager, nor some all-knowing oracle. He's allowed to get things wrong. In hindsight, it seems beyond reproach that they could've gotten the ball rolling with Lewis ~6 months earlier, even if that just meant subbing the lad on at 60 mins when we're up a couple goals or blowing out the opposition (think Sheff United in the fall)
The top managers in the world make mistakes (all of the time). Hell... Pep just sold Cole for a pittance for goodness sake. But no one thinks that calls into question his overall competence as a manager.