One mechanism to verify that is by running a mutation testing [0] tool. They are available for many languages; mutmut [1] is a great example for Python.
I see this a lot with performance measurement, for example. A team will run small-scale benchmarks, and then try to estimate how a system will scale by linearly extrapolating those results. I don't think I've ever seen it work out well in practice. Nothing scales linearly forever, and there's no reliable way to know when and how it will break down unless you actually push it to the point of breaking down.
It also reflects the domain. For mission critical code there better be 10 different layers of red lines between development and shipping. For web code, care for stuff like performance and even correctness can fall by the wayside.