Alternatively, it may be that we want to take the same 'rational' look at risk that we want the courts/child services to take. Maybe the few kids that get taken away 'unreasonably' are actually just the cost of having an otherwise sane system. Lest that come off as callous, I just mean that if you have a country of 300 million, you'll get some pretty far out scenarios played out. You don't necessarily want to add process to protect those very few scenarios that are outrageous because it may cost more (by e.g. tying CPS' hands so that they can't take actually at-risk children out of homes).
I guess I'm suggesting that this might, in the end, be much ado about nothing. It's hard to say without numbers and analysis.