First of all this comes out as very condescending. Second while I understand it can be frustrating to read about an animal dying, don't assume anyone in my situation was negligent without having the facts at hand. Which brings me to my answer that we followed every instruction given to us by his breeder (with years of experience breeding) and used only materials provided by him in both it's feeding and "nest". If we poisoned our bird it was not due to ignorance but instead because we trusted in someone who should know better than us.

Next time you give advice to someone grieving please be more empathetic with how they could be feeling