The results can be summed up rather simply:
If a university decides to use plagiarism detection software, they need to have a clear policy on why they are using the software and how they will react to the results. It would be good to set up a competence team that offers educators help in testing suspicious texts, and to perhaps have two systems on offer, as the systems find different sources for different parts of the same source.
So-called plagiarism detection software does not detect plagiarism. In general, it can only demonstrate text parallels. The decision as to whether a text is plagiarism or not must solely rest with the educator using the software: It is only a tool, not an absolute test.