This would be quite a bit more than a slap on the wrist in the US, the City of New York does all its own maintenance on all its buses, railroad and subway trains.
Manufacturer interference would result in some of the most aggressive city lawyers grinding the manufacturer's headquarters into dust, legislatively.
I can't believe it'd be different at any other jurisdiction within the US.
From the sound of them, it sounds like the polish government will take it seriously, and it can be that its going to go be an international thing too...