I think I see what you mean. I initially thought that the tap connection had to be irreversible. That rule, 250.64(C) applies to a splice in the GEC.
250.64(D) allows taps to be made to the GEC by conductors from a second enclosure without saying how, just that the GEC must be installed without a splice or joint.
I was so focused on (C) that I neglected to carefully read (D).
Thanks
