I enjoy that kind of challenge, too.
I think the scenario could be possible over the duration of a number of days (what was the maximum here? Three?) if the parental figures involved are all normally trustworthy, responsible people. I haven't discounted the possibility yet because none of them have prior records.
It's not that far of a stretch for me to believe (in the possibility) because my ex and I were very secure with each other in our custody arrangement. We lived in close proximity, but I didn't feel compelled to call them every night to "check up" or "check in" on them. I knew my son was safe and they were having a good time doing whatever.
Could it be possible all three of these people trusted each other in the same way, so there might have been no red flags?
Now, this possibility would only hold if they hadn't contacted each other and figured out the kid was unaccounted for, as the Commissioner reported. If they all knew, then naturally...there's no excuse for not following up.