Tried to read the linked article but the bias is far too odious.
I grew up in that area and am familiar with the story. I am of German ancestry too, and I wish some of those old Germans were still around so I could ask them about their experiences at that time. My grandmother and father never mentioned anything, so I don’t know if nothing happened where they were, or things did happen and they just didn’t see fit to bring it up.
This article does have an unnecessary slant that makes it less-reliable as history. The Wikipedia article on Prager is actually much better. My understanding has always been that the anti-German sentiment had become a frenzy and a mob wanted to teach a German a lesson. Prager was known because he had been involved in some local labor and political controversies and so was as good as any German for the point the mob wanted to make.