While it does not justify the completely inappropriate behavior, it might make sense to mention for context that one of the authors of the video is a right wing activist/journalist according to Wikipedia [1].
The claim that Germany is a country where foreign journalists in general have be afraid of being chased is unfounded. This was an incident involving so called right and left wing "activists."
It should be noted that this "member of the mass media" was an unpaid writer (among dozens others) on an activist blog/oped section on a large newspaper's website. He was since removed from the site because of this incident.
https://youtu.be/Io3VpyL4RoE