  A recent letter [1] investigated the effects of deuteron polarizability in
the mu D atom. The importance of understanding this atom has been heightened
because of the possible light it could shed on the proton radius puzzle. Here
we confirm, clarify, and emphasize the significance of the result [1] that the
effects of the third Zemach moment are canceled by part of the deuteron
polarizability effects. 1. K. Pachucki, Phys. Rev. Lett. 106, 193007 (2011)
