A common cure is to file a little off the side of the lever where it is hitting the hammer. Usually doesn't take too much. Can be neatly done and doesn't detract much from the gun.
It's not a mistake the maker made. These guns were designed to be carried closed and the hammers drawn on or right before a flush. I can usually get one hammer cocked almost as fast as a safety can be slid off. If uncocking it, point in a safe direction, preferably at the ground, hold the hammer and pull the trigger. As soon as you feel the sear leave the full cock notch release the trigger. With most guns should the hammer accidently fall at this time the gun will not fire but the sear will slip into a safety notch preventing a discharge.
