None of those explanations make sense to me.
If you watched the evening news, and realised that you had seen a child being kidnapped, earlier that day---what would you do?
Would you expect the police to come to your house, so you would wait for that? That makes no sense to me at all. Why not just call them and tell them what you saw?
He had evidently done that exact same thing in an earlier case.
That report to a family friend is even less convincing, imo.
He says he went to a social club to look for a family friend who was an officer, and he said he 'mentioned it' to her sister in law, at the club. That is the least reliable way of getting urgently important info about a kidnapped child to the investigators, I have ever heard.
It does not seem credible to me, because on one hand, he says he is 100% certain that it was the kidnapped child, yet on the other hand, he does next to nothing to get that child any help. Who does that?
He even knows the grandmother, so he could have gone down the street and told her himself. Did his dislike for her get in the way?