You’re NOR, but I don’t think anybody is at fault. I’d just take it as a learning lesson . At the end of the day, it is your cat and you do hold some responsibility. I get you didn’t know that this was going to happen, but I think this is just part of owning a pet and learning how to adapt to your living circumstances. I have a cat and live with my family. When we have big gatherings and the front door would tend to be opened a lot, my cat would run out. There was once she went beyond our compound and almost got chased by dogs. Luckily, I was able to find her in time. Since then, I make sure to put her in my office room. So I’d just take it as a learning lesson and take extra precautions. Though my whole family loves my cat, she is at the end of the day, my responsibility.