Well most countries handle it this way. You get your visa revoked and thats it. Pretty normal stuff and rarely is a judge involved. In the usa they dont even need to revoke a visa to throw you into guantanamo it seems. Non citizens normally dont have a right to stay in a country. It is a priviledge not a right.
I am not sure how i feel about needing a lot of evidence to rewoke visas.
In this case 3 ppl are eu citizens and the eu "freizügigkeit" needs more evidence than just allegations. However when a few neo nazi hooligans from ireland would storm into a university i would like them to be deported, especially if they dont even say the allegations are wrong. So i have to admit i am indifferent in this case.
Das wird bestimmt genau so gut annonymisiert wie die gematik akte