A sheen might be detectable in clearer calmer water.  It might be harder to detect in silty water..like the Inlet,  flowing constantly enough with the tide, to be dissipated with already dirty inlet ice.  And who`s going to "motor" in close enough to the leak to sample it?...  don`t think so. 
Questions remain... what if it progresses?..does Hilcorp have a plan B if it`s not the state`s jurisdiction to demand remediation.  There is time during slack tide to get a remote controlled vehicle down there used all the time by the oil and gas industry. It`s not cheap..that`s why the begging off till SPRING I guess. Sad commentary on our and Hilcorp`s abilities to react...to any emergency.  close-up pictures can be gotten even in inlet water..you just need to get real close.  Epic fail... like the Kullock..