AIO for ending 15-year old friendship over exposing my child to some pesticides?

I accidentally found out that my neighbour put a toxic pesticide in his garden border in place where our daughter has access and didn't tell us. She is under 3 years old and while I always watch her outside I didn't think to not let her reach there. He did it 3 days ago, she was playing in this place everyday and can easily reach there. Those neighbours are our longterm friends and our kids play often. I called toxicology service and it seems like nothing is wrong but I can't understand how little regard those people have for us and our child. Their child wasn't playing in the garden lately and I thought he was just sick. I was wrong apparently. I found out because my neighbour was livid about me leaving there some child clothes for them that I recieved a year ago and was keeping for them to give back when they have another baby. I just had to get rid of it because of not enough space in an apartment. Apparently this is offensive as I could wait and now they are a biohazard because they came in contact with this substance and he doesn't want to have it in his home. Those are little condos with tiny gardens and fences. So I wouldn't know if I didn't put those clothes in there. And the worst thing is they did not care that she was playing there. My friend is still mad about clothes and her husband even more - he was the one to handle the pesticide. I told her we have nothing to speak about if she thinks those clothes left at the garden are more offensive than endangering my child amd not even apologising. Do you think I overreacted with burning the bridges? Maybe I should talk to them if they apologise.