Well, lets look at the reasoning behind it. Presume there is an event that the ground is needed at maximum capacity... if you bend it sharp enough to deform the copper ie "kink" the ground wire, you will cause a weak point that could fail. If you have a sharp bend that is in say, the radius of a dime then, in the real world that would work to the limit that the wire was designed.
I seriously doubt any event could cause it to "arc" past the corners.
The main concern here is that your customer is the one that wants it that way, and they are paying you to do what they want, so it needs to be done to thier specs.
California definitely has some funky specs on stuff - and good ones on others
I am no electrical engineer by any means, but I think that covers it.
you need to have enough wisdom to keep from making the wrong decisions but enough courage to make the right ones
