The whole appalling event is the stuff of nightmares. Not only were the "carers" possibly ignoring what their charge could do to others , but also, in a crocodile enclosure, whst he could do to himself or the animals.
If it can be shown by CCTV or phone records at that time that they were neglecting their charge, then they must be held criminally culpable. They may be paid only minimum wage and the job is probably not respected as it should be or sufficient training given, but on that day caring for him was their job.
I do hope the little boy makes a full recovery. There is obviously so much information to be gathered.