There is more than enough evidence on the Harper tape to conclude that Harper sanctioned something that was illegal. However there is not enough evidence to prove that Harper new of the alleged life insurance offer. In fact, Harper said he did not know the details. The Liberals got greedy.
Harper is thus well positioned to win a such a libel suit, should it be allowed to go forward, well all the while being guilty as sin. It should be noted that, should the Conservatives fishing expedition fail, none of the individuals named in the suite are in any danger whatsoever. They did not write the offending article in question and while their quoted words might be libelous if said outside the House the fact remains that they said them in the House.
This new approach is a better tact for the Conservatives than trying to deny the allegations while refusing to attack the integrity of either Donna Cadman, or her late husband. Indeed without outright accusing Donna Cadman of lying, the Conservatives can not very well cite the words of Chuck Cadman as dispositive. After all, if Donna Cadman is telling the truth, either Chuck Cadman lied to CTV or he lied to his wife.
Update, I have looked at the two offending posts again. I changed my mind. I do not think the there is no there for Harper to win a label suit. That said, there is not a enough for the criminal charges to stick.