But he was skewered by equally hard and persistent questioning about the tape.
Key, meanwhile, was rehearsing his lines for what he was terming a "put up or shut up" challenge to Shearer during question time.
However, Shearer's line of questioning in the House sought to elicit information from the Prime Minister rather than make political points.
That restricted Key's ability to make an all-out assault on Shearer's credibility.
The Prime Minister was dished up one patsy question by one of his whips which enabled him to say there was no video, never had been a video and, moreover, no videos had been deleted from the GCSB's files.
But Shearer responded to good effect by cleverly lampooning Key and listing the latter's vague answers of recent weeks on the GCSB's involvement in the Dotcom case - "I don't remember", "I don't know", "Um, you know, who knows?" and "I don't remember cracking a joke about that one, because I crack jokes all the time".
So pretty much a draw - and not an especially enlightening one either.
Debate on this article is now closed.