Something to keep in mind, "casualty" would include someone who was only injured in an attack or accident. So even if the counter becomes a thing, it doesn't necessarily mean anyone died (assuming that what may have been translated into casualty actually works the same way and the author even realizes that's how the word works, a lot of people think casualties are just the dead so I dunno how well people know whatever word was in the raw). For instance, this girl was the sole casualty of the rollercoaster incident. So yeah, to actually have zero casualties she pretty much has to handle a situation flawlessly. Shy better git gud if that counter is a recurring thing.