I think the 3H bid is to blame for this mess. The NT opener does not have a super nor a mini super accept of the heart suit. Now the 3NT and 4C bids are understandable as exploratory for slam. Then, I think the 5H bid (by an overly ambitious partner) is clearly saying, "If you have diamonds stopped, I got the others." :) I think that this bidding is a roadmap for the defenders to set you. :(