It seems the Germans have been reading the Directive! Hurrah!
Bear in mind that the police in France have wide powers of stop and search and can demand to see anyone's identity documents or permission to be in the country at any time. Just something to consider if you find yourself in France without a visa and your nationality requires one. The police might not necessarily be aware of the EU family rules.
I lived in France for three years and travelled there maybe 10 times before that and I was never asked for my papers. Once I was walking near the Elysée with a Spanish national and a policeman did stop us. Then he said, "Ah, you're not French! Never mind." and waved us on.
I doubt policemen there know much about visas either. Even a non-visa national might be questioned, come to think of it.