This was local to me, so a lot of coverage. I feel sorry for the nursery, and it's important to note that it was colleagues who reported her. It was a well-regarded nursery, and I don't think we should assume other staff were negligent. It sounds as though a lot of the abuse was tiny movements that could easily be missed by others - scratching and pinching etc.
I don't know about CCTV. It's useful evidence but it doesn't address the core problems, does it? My youngest and her GCSE-dodging mates are currently all being pushed towards childcare and elderly care, as the favoured destinations for 'girls who can't do anything else' . Don't get me started on the ways our society has disemboweled life opportunities for non-academic kids, but it is such a disaster for our caring services to staff them with badly-paid youngsters.
My eldest went to an inner city Montessori which was safe and non-plastic and so, so cold ("your daughter has been doing interesting work today with lentils and a spoon, Mrs Ketzele"). My youngest was lucky to go to a local pre-school that was actually set up in the 70s as a feminist project to support working mothers. It was a bit ramshackle but all the staff were middle-aged, it had long roots in the local community and was deeply loved. No pretensions, no fancy facilities, no interest in bestowing early academic advantage, no teenagers.
You can't just magic places like that up - there are reasons why it could work and not go bankrupt (mainly, I think,because the staff had often been mums there themselves, and also because it's an affluent area so I'm guessing many could cope with low pay and worked there for the love of it). And yes, they could also have got unlucky with a staff member, as did the nursery down the road. But I think older, experienced staff are much more of an obstacle to a potential abuser.