In rereading through that article, a couple things stand out. I think often with DCFS when something slips through the cracks and a tragedy occurs, a caseworker is scapegoated and fired when it really is the system at fault.
The details here of ignoring this child's plea point in a different direction. Whoever the individuals were (4 of them, I guess) who were handling this case it seems they purposely left him to suffer.
When maternal grandparents repeatedly beg for custody of a grand child over their own daughter's wishes, and when that child IS successfully removed and then replaced with the abusive mother, and that triggers numerous calls from the teacher with very legitimate concerns - CPS workers should sit bolt upright and take note. That kind of scenario should go right to the head of the line of emergencies, over kids who may live in dirty conditions or appear to have some other lesser abuse situations or neglect.
I'd be interested after this is all said and done to hear more about the caseworker's complete neglect of this obviously horrible case of abuse.