<< You obviously did not read that section very carefully. Reading with comprehension is a valuable skill you should try it sometime. >>
And you like to insult people.
I wrote my post based on memory from having read that document over a year ago, and looking at the dates on the top of the document's pages it appears to have been revised. I was a little off on the exhaust, but they do still spend a lot of time talking about venting through the PSU, and they do still warn that in some situations, a front fan is detrimental. Previously when I had read these guidelines, they went into more detail about front venting drawing in air and how fans can disrupt that airflow.
My guess is that as their CPUs have pumped out more heat, they have had to revise their recommendations to allow for the rear fan and relax the warnings against a front fan. This was a light-hearted thread about how AMD recommendations don't always jibe with real-world practice, but it's nice that you wear your panties a bit tight.