The author of Maus is said to be mentally ill. He also said that the storybook is not based on his father's experience.
Nothing is black and white, please remember that.
In the usual Polish fashion many of You guys fail to acknowledge that apart from a significant number of brave and heroic Poles that did all they could to ease the plight of Jews at great personal risk there was also a very visible chunk of the Polish population that sold Jews out to the Nazis for food or out of spite.
But the majority wasn't involve in both helping or denouncing Jews.