Every self-reported leak, every single one ever, has been under reported.   It seems so simple, shut it down until the leak is fixed.   One thing is for absolute sure, that leak will be fixed much sooner if Hillcorp was required to shut it down until fixed.  I have no clue about the "safety issues" in shutting down this particular line but it sounds to me like they are admitting they can't shut it down if they want to.   This is just business as usual in Cook Inlet.