John Popelish wrote:
. . .
As I understand common mode current, it is the net imbalance between the
current through the center conductor and the current through the shield.

If you consider the sum of the physically separate currents on the
inside and outside of the shield to be the current "through the shield",
that's correct. And it's equal to the current on the outside of the shield.

. . .

Roy Lewallen, W7EL