Oh wow, absolutely fucking not.
The nurseries i worked in, ALL OF THEM, knew who our kids were with allergies, we knew what they could/couldn't have, we kept their eating environment healthy and safe, it was absolute TOP priority at meal times to monitor, check, and double check what they were given.
This was NOT an accident. It was negligence, and i will not accept any other explanation, and nor should the parents. there are ZERO excuses for this. ZERO.
Those poor parents.
That nursery ought to be ashamed and prosecuted.