The lancet paper has more details

https://www.thelancet.com/journals/laninf/article/PIIS1473-3...

> Evidence for 130 vaccinations in a 9 month period was collected by the public prosecutor of Magdeburg, Germany, who opened an investigation of this case with the allegation of fraud, but criminal charges were not filed.

Given the amount of information they gathered about him, it seems likely that if he was doing something illegal, they would have worked it out and charged him, I guess? It seems like an odd thing to do for “personal reasons” as they say in the paper. But the pandemic was a weird event for everybody, maybe it induced odd behavior or something like that. It is hard to say.