He was surprised Hancock hitting his smoke body, and talked about ''Kuja'' Haki as if Haki only belongs to Kuja, its open to interpretation. He definitely had some ideas but I doubt he knew about Haki fully at that point.
If he was using Haki while fighting then Hancock breaking his Haki imbued jutte is a great feat, if he was not, then Hancock should be able to break it easily so its an average feat.