Frogwares claims that at some point Nacon has stopped paying them their royalties and agreed split of the games revenue. So it's certainly true that Nacon payed for the development of the game, but it's still open whether they have really fulfilled all their financial responsibilities. That's what the courts will ultimately decide.
Oh yeah definitely, the wording is very specific "...and to date, more than 10 million euros have been paid... " which could mean they still owe 10mill more.
Your right will need to see the results of a court case.