I don't see it that way at all. Any parent given the circumstances would jump to the same conclusion that someone had abducted her. Unfortunately or fortunately, depending on your point of view, the evidence does NOT support an abduction.
In fact, contrary to what you posted, there was no need for any lie. Mistaken would be a more appropriate qualification.
In the final analysis, it was the guilt of having left her unattended and the possible legal consequences of having done so which concerned the tapas group more than anything else. Thus we have the ass covering exercise in perfect parenting!
I'd thought about that, but then why would they all admit - at the first opportunity - that they'd all left the children unattended in between checks?
IFF they had all pretended that they'd ordered take-aways and had never left the kids alone ever... then, yes, I'd accept that they were in denial, but that doesn't appear to be the case.