From my philosophical point of view:
I think the thread should not have been removed. If the lawyers of Ryanair disagree, they are free to post their view on this board. This board is about discussion and opinion. There's i.m.o. a clear disclaimer below each page, this BB is clearly not resposible for the contents of what is posted.
Then again I am unfamiliar with British/Irish law. Maybe it would have been sufficient to remove the name Ryanair from the discussion regarding libel and slander?
From my practical point of view:
I personally don't care too much what happens with Ryanair, and wouldn't be interested in taking any hits from this. This could ofcourse work as a precedent for future disputes.