In the Black Mirror Episode "Nosedive (S3,E1)", towards the end, Lacie's rating falls below 1 and goes to a '0', thereby sending her to a jail of sorts.
In the app that they use to rate each other, the minimum rating you could give someone would be 1 star highest being 5. So a person could go to 1 (but to be honest even a perfect one is impossible since she always had been a 4.2, mathematically she would always be a 1.00000something even if she got all 1s in a row)
My question is how did she fall to below 1? Since the lowest rating one could get is 1, how did she end up with a 0.something? Did I miss something?