That seems like evidence at a first glance - until you remember the whole Amazon Lily island can use haki. So, it's really nothing so uber special.
Haha, yeah. I was trying to think back to that earlier, but, alas, my memory fails me so miserably I couldn't recall anything so specific from the arc. Though I still don't know why Lucci would be an exception intrinsically (considering this haki/not haki discussion). Using a zooan fruit power should make zilch difference in that sense. He just had to use the power because Luffy was too tough to beat otherwise.