Maybe it wasn’t the dogs getting confused by the parents scent that made them suggest parents didn’t search - it was more they didn’t want any suggestion of innocent post-humous contamination for any evidence that is/was recovered.
[Bolded & Underscored, for emphasis, by me]
Also, from video at same link ---
WKRN Reporter Andy Cordan:
"I can tell you that emergency crews were notified at 6:22 in the morning, but the Sheriff tells me that the boy's family woke up for school, they looked for their little boy, they didn't find him and instead of calling 911, instead they started searching around their house and almost an hour was lost."