What really caused the eurozone crisis?

Surprisingly, according to the BBC (see http://www.bbc.co.uk/news/business-16290598), it was all down to the private sector borrowing recklessly when interest rates were low due to southern European countries joining the euro. And it was nothing at all to do with the governments of these southern European lying about their financial health, and the northern European countries ignoring the lies. Which leaves me wondering if the BBC is using Gordon Brown, the man who never made a crazy decision (apart from selling off Britain’s gold, and recklessly spending the money he got from stealth taxes), as a financial advisor.