I don't think the surface was damaged by over dipping, But that the surface was already damaged due to heavily toned/corroded nearly black like the few black areas left. The use of dip removed most of that, but the thin films that were left produced the dull pinkish/gray tint. The end result is the same, but I don't think dip can be blamed as much as the corrosion done before the dip was used.
Very likely Jim. When I said overdipped, I was not blaming the dipper necessarily. I have overdipped coins exactly like you described. If I hadn't, the coin would have just corroded away to a black blob.
Probably a blast-white coin that was retoned artificially (probably left in the sun causing accelerated toning).