I have never flown a S-76 and was not around when this happened. I do find it curious (if true) that a distress call was made and a split second decision was made to ditch 20 minutes later.
I flew B212/214ST and SK61/76's offshore for donkey's years.
If you lose tranny oil pressure, reduce power, descend to 50' Rad Alt and head for nearest land (or maybe boat/rig, depending how far out you are).
Call flight watch and tell them you have a problem that may require ditching.
If the tranny starts making really expensive noises put the rocket in the water - IMMEDIATELY.
Is there something about this scenario that eludes you?