Joseph,
I was responding to a post by mik5 who was upset about seeing people shaking hands with women. My point is not to advise anyone to shake hands with women, everyone should ask their own shaila. My point was this: “Bottom line, don’t get upset when you see frum Jews shaking hands with women. Dan them l’kaf z’chus that they asked their Rav before doing so and know that yesh l’hem al mi lismichu.”
Now, as it happens there is a machlokes haposkim about whether derech chiba is an objective standard or a subjective standard. Arguably it is a machlokes between the Mechaber and the Rama. And the Toras Hashlamim (Yoreh Deah 195:15) certainly seems to hold it’s subjective. The posek under whom I learned holds that derech chiba is subjective (as does Rabbi Yitzchak Weinberg in his sefer on yehoreg vaal yaavor) and therefore when it comes to shaking hands a person must make a split-second asessment. I am only not mentioning his name because it might identify me.