The productivity is measured in an abstract unit (currency), not the actual quality and quantity of product - thus it is open to distortions (such as abnormally high foreign investment).
If we ignore the numbers and just look at the situation a little more generally then, Spain has gone through a massive construction boom that was typified by speculative overbuilding, which is part of the current problem now that too much has been built and the real estate prices have collapsed.
Building far too much is not often associated with lazyness on the part of the workforce.
