Someone asked Rush that once and he said it was a jab at her for her political views. I think he doesn’t have to pay as it is just an excerpt.
Actually, after years of not saying anything, that jab from Rush made her come after him. They worked out a deal where Rush pays out to PETA, believe it or not.
http://www.rollingstone.com/news/story/5923659/really_randoms_chrissie_hynde_ricky_martin_jimmy_page