When refactoring goes bad..

Sometimes during refactoring - especially when you change the condition of a function from true to false or vice versa, and you get distracted horrible things happen. Can you spot the error in this piece of code ?


Yup. Ouch. I did this, And of course it lay in wait and slapped me hard in the face as soon as a customer pressed the button. Ouch. It happens to us all, and you'd think I'd have mastered this 'measure it twice' malarkey...