It sounds as if Yanmar tried the standard summary judgement ruse by saying they didn't do business in the jurisdiction (while admitting they did sell parts and they did know the tractors were being sold). Sounds like a reason for the certified letters to the US yanmar dealers not to sell parts for grays or they would be dropped as dealers. Now they are actively trying other defenses to try to shut down the market. I will bet since they new in the past that the tractors were coming in and that they were selling parts, they are on the hook for liability. Now they will try to keep the trade down, not sell parts, and shut down all support. Mostly they will threaten people, but occasionally will sue. It will help to prove that they are not willing accomplices and limit the liability for future suits.
I am guessing that they lost the suit--as I am sure the models were never even evaluated to see if they conformed with US safety standards.