That last bit is the main reason why I use odd or otherwise out of place test data[0]. Test data should never leak into production. Ideally there should be no means of that happening.
[0] Recent example: tissue sample, species: dog, tissue type: bone. Valid combination, just not present anywhere in prod.
[0] Recent example: tissue sample, species: dog, tissue type: bone. Valid combination, just not present anywhere in prod.