It doesn't seem they can. They told readers that Colombia's GDP has doubled since President Uribe took office in 2002. That's not what the IMF says. According to the IMF, the increase has been just over 40 percent during this period. That's respectable growth, but it sure is not a doubling of GDP.
Calculating real GDP is a recurring problem at top media outlets. In December of 2007, in order to argue that the case that NAFTA had been a great success, a Washington Post editorial told readers that Mexico's GDP had quadrupled between 1988 and 2007. In reality, the increase had been just 84 percent. While a huge "nevermind" would have been in order, the Post lacked the integrity to print a correction and own up to this mistake.
[Addendum: BusinessWeek has corrected its mistake. We're still waiting on the Post.]