I've thought it odd that Patsy told the police in 1998 she didn't pack a suitcase for their planned trip that day, she was gathering clothes together for all of them in a plastic bag when she 'found' the ransom note. She said they were only going for a couple of days or so and they had clothes at the lake house. Now this was their first winter trip to the lake house, previously they had only spent summers there. So to me it seems clear they wouldn't have stored winter clothes at the lake house, and also children quickly grow out of clothes, so why leave any behind? There was a plastic bag of items dumped at the bottom of the spiral staircase, photographed that morning by police, and she said that was probably it, that she had dropped it to read the note.
I wasn't 100% certain from the interview transcript but it seemed to me that after giving her explanation for the plastic bag, the police then confronted her with a photograph taken on her own camera by someone in the family on Christmas morning, which showed the same bag she had referred to in the exact same spot already, and couldn't have been the plastic bag she was filling with clothes. She was stumped by this and couldn't work out who in the family would have taken a photo of just the hallway, but more to the point it blew her explanation.