Older dog drop-ins-stroke?

You should have been 100% honest with the owner. You are dealing with living things. Frankly, if your social life or full time job is preventing you from caring for a critically ill animal with a medical EMERGENCY...you should rethink Rover. Hope the dog was OK.

It sounds like it's past the time of your drop in so hopefully it got resolved and the dog is well. My recommendation for any issue like this is to call Rover support. They should be able to advise you on how to best handle (for example if the dog should be taken to the vet). You don't have to answer, but I'm curious if the expectation was that you'd be there on NYE? If you had committed to being with the dog then that should have been the priority; if you hadn't committed to being with the dog there shouldn't be the expectation they would. Though, if the dog is very sick and needs some kind of medical attention I'm sure there is some way Rover support could have helped you work it all out. I hope you had a very happy new year!