I think Hansson knows that mistake against Ireland has ruined his career and reputation. But, professional referee should try to avoid a crisis in his form and fitness. It is a bit stupid to give up after one poor performance...
I mean if you work for years to be one day in charge of a World Cup game, as it must be also a deeply mental process, and then such a thing happens. Anyway, he was part of 2010 World Cup, I think he should be proud of that!