I have a mostly unfounded hunch that there is something significant about Thursday night. I think, IMO, JMO, there might be a reason why the parents either told LE they arrived Fri AM, or let LE believe that, to the point that they didn't bother clarifying in their interview, or in SM, and LE had to find out during the course of the investigation otherwise.
Without even knowing much about the case, when I saw the parents' interview with NE, I got the feeling that DK used the opportunity Nate gave him to address any rumors to point out the rumor that a clerk had seen them at the store (but it was the wrong time). I wondered, out of all the terrible rumors, why address that one? It seemed like it was really important for DK to explain that they WERE at the store with DeOrr. (I also think that later adding that there was a man staring at DeOrr at the store added more detail to make it even more sure he was there.)
So, why is being seen at the store with DeOrr on Fri so important to the parents? Is it because IR did not see the toddler at the campsite on Fri and so the parents needed proof otherwise that DeOrr was in Leadore before he went missing? Is it because LE told them that no one in the store recalled seeing DeOrr with them? What was happening Thurs night at that campsite? Does GGP remember the last time he saw DeOrr? When did IR last see him, or see him at all?
I wonder if the FBI are re-interviewing the POI's or if that was just their suggestion to LE. It seems the case is still going in a particular direction but there is not enough to go on to conclude anything definitively or press charges.