Just this month, there was a court case in Switzerland where an ATC was charged and convicted because he gave wrong instructions to a military jet, which then crashed into a rock wall. The case was quite interesting to follow, due to the various implications of a conviction or acquittal. It had quite some media coverage.
(Note that this was a military court, not a civil court. Proceedings might be different in these cases, even though both civil and military ATCs work for the same company - Skyguide.)
https://www.swissinfo.ch/eng/swiss-military-jet-crash--publi...
https://www.swissinfo.ch/eng/air-traffic-controller-blamed-f...
(Note that this was a military court, not a civil court. Proceedings might be different in these cases, even though both civil and military ATCs work for the same company - Skyguide.)