Wrong. Because left hand muting.
Good point!
Although, I could make the counter argument, if you are using the "left hand muting" technique (which not all players do) then whichever fingers you are "using" to mute are not, technically, "unused."
So I would stand by my original "Devil's advocate" statement, with the slight clarification, "It is perfectly okay for your unused fingers (i.e. fingers that are neither fretting a note, nor muting the unplayed strings) to go wherever they feel most comfortable."



