Yes, what happened in Crimea was bad.
But concerning war-prisoners, soviets were much worse. Also western allies were not saints. When there was civil war in my country 1918 Finns cutted heads off from their own brothers (war-prisoners too), just because in war enemy-soldier is sometimes just enemy.
Interesting thing is Norway, where only ethnicities who did not rebel against Third Reich were Kvens (Finns) and Saamis. Germans threated them much better than they threated Norwegians.