I think it may vary by jurisdiction. In poorer areas where there are plenty of families with real problems, and case workers are overloaded, removal is probably an option of last resort. In towns where they sit and twiddle their thumbs all day, they might jump to remove kids if Mom let a 12-year old bike half a mile to the corner store (I think I remember a story like that from Connecticut or Maryland). I know I lived in a town where every time there was any kind of road work or utility work, there were 2 police cars hanging out at the scene, because the total crime rate for the town was something like a dozen per year, and that included someone pouring a milkshake over a parked car!
But Sean wouldn't have qualified anyway... and I think he was doomed. Some people cannot be saved, and probably not worth the gargantuan effort required to save them.