deadsea - 2:05 pm on Sep 11, 2013 (gmt 0)
There is always the case of 301 redirects and the amount of pagerank they pass. That is an instance where Matt Cutts stated that he previously gave out wrong information, but it was time to correct the record. Here is the admission video: [youtube.com...]
In this case he appears have have used simplification in his previous statement that made it untrue. He had said that using redirects will cause some pagerank to evaporate, just like using links. He later said that this is technically untrue and that he meant that that there is no way to use redirects instead of pagerank to prevent the evaporation of link juice. He now says the redirect itself doesn't cause any pagerank evaporation. (This is all paraphrased, and the issue could still use a lot more clarification from Google.)
I believe that Google and its representatives use omission, simplification, and white lies fairly frequently.