To me it sounds like their reaction to a really traumatic experience sucked. It's so hard to lose a pet and it's made worse because they didn't seem to understand what you were going through. As someone who accidentally let my dogs out of the gate when I was a kid, and one got run over, I empathise with anyone who is traumatised by an event like that. I don't think that my dad forgave me for that, which I think is wrong. But you know, these were adults it's up to you how much slack you cut them. I was too young to control my dog when it ran out, and accidents do happen. But even as a 20yo I think I would feel very guilty if this happened on my watch and I would feel the need to apologise profusely.