I think it is entirely fair to point out his lies and factual errors. Just because we all know on here doesn't mean that Joe Public isn't taken in by him. As long as we keep balancing his tosh with facts, we will counter his anti-RAF propaganda.
If you search "Sharkey Ward" on Google, P Prune is the 3rd reply headed "more RAF bashing from Sharkey" so at least we stand a chance of folk realising that he spouts utter bolleaux.