Did not stay overnight for one night during pet sit.

Just wondering what you would’ve done in this situation. I was in the middle of a 6 night dog sit when on the 3rd day I popped home to check on my senior cat. I don’t live far and my boyfriend cares for him while I’m away. Well, my cat was doing bad. He was 19 and was slowly declining, but when I saw him that Friday I knew it was time. I cried my eyes out scheduling him an at home euthanasia appointment for the next morning. I contacted the dog owners and let them know that there was no way that I couldn’t spend my boys last night on earth at home with him. I had contacted their main walker and the other members of my pet sitting collective , but no one was available to spend the night. I let the owners know that I took their dog out at 9pm and arranged for a fellow walker to come back at 7:30 am for breakfast and morning walk. I told them I would be back at their house to resume the dog sit at noon. The owners were pretty understand, but after the dog sit spoke to my teammate (their main walker) about our lack of plan during an emergency. I feel awful for leaving their dog alone for one night, but I really don’t know what else I was supposed to do. Do you guys have a written agreement about what happens in the case of an emergency like this?