Clarke will have some trouble walking back his own admissions if he's going to argue that. While he's denied some, he's admitted sexually harassing staff, admitting making actors submit to nude auditions, and admitted filming material that was essentially pornographic with no prospect of actually being included in his films (though on that count he fell short of admitting it had been for his own gratification.) His response on the issue of sending unsolicited pornographic pictures of himself to employees won't impress a judge either (he couldn't remember the specifics well enough of if he'd ever sent a particular picture to a particular woman).
In my opinion he's just opening himself up to further personal and professional humiliation. Not only is he facing the prospect of pictures of his dick being passed around in court, but he's setting the police up to be asked the question he really doesn't want them asked. Because whether detectives found the allegations not credible, or credible but not crossing the threshold into a criminal offence will be key. Clarke had obviously been trying to play the perceptive wiggle room that no prosecutions meant the allegations were unsubstantiated by the police. But this libel case threatens to destroy even that fig leaf he's got left.