My apology I neglected to answer the original question. I believe that Limbaugh knew about Sandra Fluke's background and chose words that fit both her real position or purpose for testifying and the usual reason it is used
Personally I would have not used those terms and a good wordsmith would have made the same point with humor and cemented agreement.

But like George Bush and Sarah Palin liberals will continue to kick Limbaugh down merciless. It will be never ending.