Definitely the Vatican should be catching some flack over this.
Look at the Bishop's interview:
http://www.youtube.com/watch?v=YHhdBzPH_zM
He's got to have a loose marble rolling around in his head. There were plenty of people who came out of the camps and soldiers from foreign nations who freed people from the camps that witnessed the conditions.
Also his point about the deadliness of the gas is true but the question really is about how tight the seals were in the chambers. The Nazis themselves forced Jews to be the workers in the camp so they didn't have to run any extraordinary risks around the gas chambers themselves.