It's odd - this strikes me as something that could be a genuine reaction in a vulnerable situation: a person is frantic with worry over their kids, and is also being disbelieved by people close to him. And perhaps IF he was not approved of prior by those close people to the disappearance, the sensitivity to being rejected yet again is close to the surface, making that the first thing he speaks of. Or he's frantic to have someone, anyone believe him, and is dismayed that people he knows (rather than strangers like LE) are not believing and therefore contributing to delaying a search/investigation in the right direction.
I'm not sure I expressed that very well - in short, could be a natural ADDITION to needing everyone to believe him so that they'll all search for the kids or search to find out what really happened to them
All hypothetical on my part - that is, IMO