There was crossed testimony under oath that (1) the RV was parked in the neighborhood and near the playground at various times and (2) that the RV's door was at least sometimes left unlocked. That is known as indirect evidence. Common sense is the glue that allows one to stick a child in the RV for the purpose of assuming innocence -- which is what if a juror acting in good faith and duty you are under sworn oath to do.
Remember I first and foremost concluded that the evidence found is not consistant with Danielle playing there at all. This is key.
I feel that even if she did play there before the evidence left is not from that visit. Second, even though the RV may have been opened there must be at least one child who was in there besides Danielle. The fact that the defense hasn't gotten at least one child who played there or one parent who saw kids enter there is telling to me that the defense is blowing smoke.