Shoe-tying order when tying another's shoes

Question

Shulchan Aruch, Orach Chayim 2:4–5:

ינעול מנעל ימין תחילה ולא יקשרנו ואחר כך ינעול של שמאל ויקשרנו ויחזור ויקשור של ימין

One should don his right shoe first but not tie it, then don his left and tie it, then tie his right.

Mishna B'rura explains that we tie the left shoe first

דלענין קשירה מצינו שהתורה נתנה חשיבות אל השמאל שקושר עליה תפילה של יד

because regarding tying we find that the Torah lends importance to the left, for we tie the hand-t'filin there.

He adds that

ואיטר יד שמניח תפילין בימין של כל אדם יקדים ימין גם להקשירה

a left-handed person who wears t'filin on his right should also accord the right precedence for tying.

Thus, a left-handed person ties his right shoe before his left; a right-handed person ties his left shoe before his right.

Suppose a left-handed person is putting and tying shoes on a right-handed person's feet, or vice versa (a right-handed person is doing so on a left-handed person's feet). What order should he do so in?

I'd appreciate any source that discusses this (though B'er Moshe (the Debreciner), volume 2 number 3 section 1, and Yad Eliezer (English, Rabbi Krohn, fifth ed., 1996), section A-14, do not), or arguments in support of either position.

Answer 1

I think the standard when putting t'filin on another person is to put it on a right-handed person's left arm and a left-handed person's right arm irrespective of the handedness of the one putting it on him. Since the order of tying shoes is derived from the arm on which one puts t'filin, I propose that it depends on the handedness of the one wearing the shoes and not on the handedness of the one tying them.

But that's based on nothing beyond what little intellect I can lay claim to.