"says he can't UT shearwave this connection from one side, that he is required to UT it from both sides."-quote
Does he mean from one side of the joint(weld axis) or one side of the material?
You can't always get to both side of the weld axis either and if you look at Fig. 6.21 Note 2, it says to test from both sides of the weld axis where ever mechanically possible, so it is giving you an out if you can't get to both sides of the weld axis.