Both countries had higher life expectancy; Iceland had higher school enrollment.
You see, having a higher per capita GDP doesn't make the country more developed, per say. Rich people have more money than poor people. Yet, both can afford to study and have a nice life, because the country provides such matters.
The economic issue is that if ten people are richer than a thousand people in the same country, the per capita GDP in HDI will evaluate the rich ones, sharing the money at the statistics, but not in reality. It's not the money you have, but the quality of products offered for you to expend it the most profitable way.