Exactly what I was trying to say earlier.
It is NOT illegal for Germans to Play.
It is however illegal to market. The fact that the casinos have a German section is not enough for the authorities to do anything. You may not have a .de domain and definitely not market in Germany itself without a licence – Affiliate or Casino. Affiliates need licences as well.
But as long as you do not live in Germany, and do not own a .de domain.. there is little that they can do.