Slightly misleading, as he was sentenced to three years in prison, they just didn't find him guilty of "aggravated" rape. Which seems to have been the right call, since the definition for that is strict in the law, and those definitions weren't met.
The issue is that he could've been sentenced to ten years in prison, but the courts gave him a punishment from the lower end, for some reason.
The law is being amended because of this case, though, and in the future cases like that will be "aggravated rape of a minor."
Pretty cool that countries have to update their rape laws because of refugees. Multiculturalism, such a richness.