I don't think you can assume that just because the service dog made a mistake one time. I train a different type of working dog and used to work with a trainer who trained a lot of service dogs. Even actual service dogs sometimes make small mistakes on occasion, even the best-trained ones are still animals after all. I've also been hearing a lot about service dogs needing refresher training as lockdowns are ending, because it's not like you train a dog once and it's done. It's an ongoing practice that needs to be maintained throughout the animal's life. So a number of people are finding their service dogs got rusty when they weren't going out in public much during the lockdowns and are excited to be around people again.