Poland was in no way responsible for the holocaust and it was a monumentally stupid thing to say but there was, and is, a very nasty streak of anti-semitism in Polish culture. I've spoken to Poles who suffered terribly at the hands of the Nazis but didn't think getting rid of the Jews was such a bad idea. Some years ago, the New Yorker magazine carried an appalling article that documented how the people of a certain Polish village, with little more than a nod from the Nazis, rounded up their neighbours, locked them in a barn and burned them alive.