Sam Wallace: Keys' desperation to have his say was the decisive nail in his coffin

As an experienced journalist at the centre of what he described himself as a media "firestorm", Richard Keys should have known that the more he said yesterday, the deeper the hole would become but, consumed by the desire to speak his mind, he forgot that most basic of rules.

Famous as he is for never using a script when he has presented Sky Sports' coverage of the biggest matches over the last 20 years, this was the one occasion when Keys would have done himself a favour by sticking to a few lines proscribed by his lawyer. By the end of more than an hour in the talkSport radio studio, he had not so much given legs to the story of his sexism scandal, as jabbed it in the side and shooed it out of the field.

He came to apologise for his original comments, secretly recorded before Sunday's game between Wolves and Liverpool, about the female referee's assistant Sian Massey. And he did so repeatedly and without reservation. It was the bits between the apologies that caused all the trouble.

In seeking to explain his position he hinted at a secret conspiracy – "the dark forces" – that had prevented him from apologising earlier in the week. He claimed that sexism was rife in the Manchester United dressing room. He apologised to Karren Brady, West Ham's vice-chairman, then claimed she had used his disparaging remark about her to camouflage the club's current problems.

In the lingua franca of an industry obsessed with public image, Keys had "gone rogue". He even compared his own trial by leaked footage to the phone-hacking scandal that is consuming Sky Sports' parent company News Corp. One can only imagine how Rupert Murdoch's executives felt about that.

"We do live in a democracy, there are two sides to this," Keys pleaded. "Please, we've heard one a lot, let's hear the other one a little bit."

It was, in the modern parlance, car-crash radio. This was Keys' Alan Partridge moment. Or rather it was comparable to the moment when Alan goes on air to apologise to Norfolk's farmers only to abandon the apology midway with disastrous consequences.

At one point in the interview, Keys was interrupted by one of the presenters who read out a statement released via Andy Gray's lawyers expressing, briefly and succinctly, his own regret. "Well, it's kind of saying what I have," responded Keys. But Keys said so much more.

The contradictions were hard to ignore. On the subject of his beloved "banter", as he described it, Keys said: "There is a wider conversation here about is it sexist? Is it lads' mag banter? Is there a place for it? That is not for me to judge and this is not the time for that conversation." The answers he was surely looking for were: yes, yes and no.

Even then he must have known then he was on his way out. There was a screw-you-moment to those at Sky who stitched him up – "Whatever happens next they will never take those 20 years off us" – and a reminder to others that they had drunk at the "well" of success dug by him and Gray.

Keys has always been the most cautious of presenters, never becoming embroiled in any public rows beyond the odd unguarded comment recorded on a microphone. His personality has never been a feature of his presenting. Not until now when, finally let off the leash, he has let rip on 20 years' worth of conspiracy theories and animosities.

Keys has had a ringside seat over the years, watching various figures in English football hang themselves with their words, none more famous than Kevin Keegan's rant in 1996 about Sir Alex Ferguson broadcast live on Sky Sports. But it did not stop him repeating the same mistakes.