When asked if he had anything to do with the children’s disappearance, he was adamant in his answer.It might just be the way he talks, but that last line and the "probably be looking for the rest of my life" makes it sound like he doesn't think this case will ever get solved for some reason.
“I 100 per cent did not and I will hold that to my last day on this planet,” he said.
Sounds to me more like he is saying he will stick to his story of not being involved till his dying day. Not that they will never be found... Very different thing, I think. He doesn't know if he will live for another 5 or 50 years, but either way, he's not changing his story.