If a health department finds that a restaurant is too dirty to operate, they don't jail the workers or the workers but fine or shutdown the restaurant.
This is a similar kind of an order - the best county could do is to fine Tesla or shut them down.
There have been countless discussions already about at risk groups and potential spread to them, QALY's, etc. What I want to get at is "social distancing" is arbitrary (6 feet?) and should not be forced. (I am unsure of your statement "Refusing to social distance is illegal...")
But the state is willing to make some exceptions, making it legal for this.
There do exist concrete studies on what distance makes sense; see for example https://medium.com/@jurgenthoelen/belgian-dutch-study-why-in...