That’s a good point and I would to add a detail that foreign readers may be missing. In Germany it is illegal to insult anyone. Actually there is a separate case revolving around this initiated by Erdogan in his capacity as just some guy and Merkel is not involved in that. That explains why the lèse-majesté aspect has attracted only limited attention in the past. It is an obscure specialization of a largely uncontroversial general concept.
And that ties into what you described. In practice the system operates under the assumption that usually there is more to insult cases. They can be a small part of a larger dispute, e.g. in the workplace or between neighbors, it covers various low-level cases of things like slander, assault, battery or sexual harassment. And sometimes it just means that you pissed off a cop more than was wise. Of course there are possible defenses like a legitimate interest or implied consent.
So it was Erdogan who rocked the boat when he reacted inappropriately to the initial perfectly harmless and legal Extra 3 video. In doing so, like a heckler at a comedy show, he pretty much asked for more. And Böhmermann was more than happy to deliver.
