Does development of sim includes empirical test?

[Armatian]

I really would like to know, specially from someone close to the development of sow, if simulation engines get some sort of basic empirical test.
I'm a sim fanatic since 1989, and got used to rapidly test some basic things, like free fall from known altitudes, doesn't matter a car or a plane, and aproximattely compare to "real" (not every object fall at the same rate)
It's not the definitive test, but just an example of what kind of testing i've done to have an idea about attention to detail.
Does a simulation get physical features tested on a large scale to detect errors?
Or better, do any physic related bug got detected by a casual sight or a subconscious level?
I always thought that realism need as much accuracy as the hability to make that accuracy perceivable.