IMO, when the Police knocked on his door last June it took him totally off guard. After 24 years of silence, he was absolutely confident that he got away with everything concerning MB.
His first reaction - deny everything! Then he did some fast googling and he listened to the podcast. Realizing that LE could connect him to MB, he came up with the first version of his story, hoping he could place all suspicion on the mysterious pilot. He was in damage control and didn't know for sure what witnesses or evidence LE and SL had to connect him so he tried to cover all possible bases.
As time passed and he realized LE had very little solid proof, he re-wrote his story to fit, what he thought, were the known provable facts.
With no credible way to explain his first 'fairytale', he took the ludicrous option of denying he ever made that statement in June thereby suggesting LE fabricated the statement and tricked him into signing it. His solicitor disappeared!
Now, we wait, and hope he hasn't covered all bases! 15 days to go...