Slow driver on the left track

After the Drängler discussion found so much support, now the opposite. Yesterday I drove on a three-lane highway about 160 km/h. On the right lane, because no traffic. In front of me on the left lane I pick up another vehicle. On the right lane also trucks appear now. I reduce my speed and switch to the left lane (meaning continue free). Then I drove with due distance behind the left driver. He drove 120 km/h. I didn’t overtake the middle lane on the right, because I didn’t allow it. After about 5min I get noticed and then the left-hand driver changes to the middle lane and I can overtake. What would you have done? It was a clear violation of the right-hand drive. Is this a coercion in such a case? I’m really curious about your opinion. Oh yes and I don’t want anyone to feel provoked by this topic. Is just a general opinion. ße Selenum