I still remember when Christian Scientists were withholding medical treatment from children.....and there were court battles over their right to do so. I am not sure how far the law now goes to decide 'exactly' what degree of 'faith' is permitted before medical treatment is required.

The whole issue of where regular religious beliefs leaves off and delusion begins is always awkward, because it operates on a continuum! The Heaven's Gate group was almost universally admitted to be delusional cult led by a charismatic personality. The Christian Scientists seem to be borderline, while the Jehovah's Witnesses, with their unusual beliefs about the nature of Heaven, seem to be, legally at least, on the 'safe' side. And Catholics, with belief in transubstantiation, are judged to be quite sane...by most.

All we are really arguing about is the gray areas..... and the details of the argument depend on our individual sensitivities to 'grayness'. And, in almost all debates about subjective issues, we find unstated premises behind folks' overt claims, beliefs and opinions.
   Often, it all depends, as the old saying goes, on "whose ox is being gored". When one person or group sees a potential for a court ruling or new law, even if not directed specifically at them, to interfere with their perceived 'rights' or behavior, they object.
   We see this in debates over gun laws; over red light cameras; over roof color rules in gated communities...and BOY do we see it in debates that might affect religious rights! In guns, traffic laws & roof colors, there are at least obvious standards and reasons to refer to....that can be POINTED at. In religious debates, the ultimate claims are not subject to any test, and have thousands of years of cultural norms as shelters.

In a totally neutral, scientific analysis...(theoretically), of course any non-'provable' belief suffers from some degree of delusion! But the courts and laws are created & administered by humans who almost always have some of the 'un-stated premises' in their own belief systems.

What it all comes down to is similar to the old definition that "a trial is a legal procedure to determine who has the best lawyer".

Until reason is TAUGHT in enough places to replace 'wishful thinking', we will always have these quandaries. The most egregious cases, like this one about this poor child, will get 'justice', and less clear abuse will continue be ignored.