To me the code isn't entirely clear (go figure) on whether the boring of a plate more than 50% requires the tie on one or both sides. (The exception refers to a notch or cut, not a bore) And without knowing whether the code is designed to resist an imposed load that is intended for tension, gravity or lateral I have assumed the code intended for both sides to be protected from failure. The sheathing would eliminate the need for a tie on the side that is sheathed but would do little to strengthen the side without sheathing and if the force is from the outside pushing in, say from wind, you end up with essentially nothing to resist that force where the code intends a plate (or double plate) to resist that force. That is my assumption and maybe it is an overly cautious reaction, but for the cost and time involved it seems reasonable until I am shown the error of my thinking. I don't have the commentary with me but I will check again.