Agreed
While the defence is not under a burden to prove anything, if they want to raise a reasonable doubt - a real possibility that Chad was not involved, IMO they need to be able to point to some factual foundation to address your last sentence. We have Chad on video in Hawaii, living it up without the kids. We have him recorded on a phone call with the kids missing, failing to address real concerns in any sensible manner. The only natural and obvious inference is he did it.
For him to be innocent, there has to be some kind of explanation he can point to, about how LV deceived him. Where will that come from? Where did he think the kids were, if not in his yard?
I don't see them raising any real alternative.