BBC CWR - extra faders open during the news

Why is is when faders are left open, or studios which should not be live are live, it's at exactly the wrong moment? Sadly, it's happened to most of us. Witness this news bulletin on BBC CWR on 3rd March 2014. And the apology which followed.

One gets the feeling the newsreader was not listening off-air. Would that have made things worse or better?