Your missing the point, mate.
The rules regarding the posting of defamitory and potentially slanderous comments against businesses, are very very clear, and have been around for a long long time. By using this forum you agree to abide by the rules that Prank, as the forum owner, has set out. They are the rules, end of story. While in theory yes we should all be able to post 'truthful' comments, the fact is this is the internet, and nobody really has any way of knowing just how truthful, or otherwise, a comment may be. Sadly there is almost always more to the story when something is posted, and the real facts have a habit of being exaggerated or embellished.
At the end of the day, Prank is liable for any comment resulting in legal threats/action against SAU, and as such the above rule is in place to protect both Prank, and the forum as a whole.
If you choose to ignore the rules, and you are issued with a warning, there is only one person to blame, and its yourself.