It sounded like he was about to say 'legal', got halfway through and changed his wording. Have a listen on Jeremy Vine - the AoC is on after 1 pm news and the wedding comes up at the end of his chat, at about 13.20.
I honestly think there was some sort of reading of vows in the garden, and I also think the legality of the Saturday wedding is questionable, possibly for a completely different reason, and AoC is having to dance around something.
He does stutter a bit sometimes in his usual speech but I listened to it and he was about to say "legal".
I think he probably did just bless them after saying personalised vows in the garden but was content for them to think that was their wedding. And the Sussex team also said the same thing. Which is the only thing they've backtracked on. But him saying that he can't talk about what actually happened is raising eye brows even though vicars are supposed to be confidential.
He does again say that it would be perjury to sign a false wedding certificate and that includes a backgarden Church of England "service" without witnesses. They can't play act out vows they've already done once before.
However his precise wording sounds like he's trying to hide something, even if he isn't. Because if he did do the full thing through twice then the validity of the St George's wedding would be questionable. And the AoC would have "married" them illegally knowing that he shouldn't. And he would be in a lot of trouble.
If there was a legal wedding in Botswana then it would be considered valid in the UK and all the should have had was a blessing in the Chapel. But I'm not sure that's what he's talking about because no one in the media is asking about Botswana.
I don't know, it's good enough for the media to start calling them liars though.