I agree. IAAD but not in US and not involved in this case.
When you practice medicine you are always surprised at what you find and you would not believe some of the things we see.
Patients in wheelchairs who are physically and neurologically normal. Patients who present with strange and catastrophic conditions who then turn out to be known Munchausens.
In the case of adults if someone chooses to do strange things we do not have any interest or right to stop them, providing they are not harming others.
However in the case of children, if we believe that illness is not present, and therefore that the child is being harmed by the presumption of illness, then we have a duty of care to the child to prevent it. It is not negotiable - we have legal and moral duty to do this. An example of this is children whose parents poison (and sometimes kill) using salt. These situations are very rarely immediately obvious.
This guy has taken on himself to judge this difficult and messy situation, and unless you are directly involved in the case and have some expertise to bring to the table, a lot of people would agree with you that this indeed makes it likely to be a jerk.