Doing a Winston?

Today in question-time, Rodney Hide and Judith Collins used Parliamentary privilege to accuse David Benson-Pope of assaulting students when he was a teacher in the 80's. The allegations are serious, and describe behaviour that was illegal even back then, and I'd suggest that if Collins and Hide have any real evidence, they should take it to the police (and Benson-Pope should be charged, tried, and if convicted, kicked out of Parliament). But otherwise, they're just doing a Winston - making false allegations under the cover of privilege, secure in the knowledge that they will never be held to account for them.