To proceed:
Helmetfire makes the following claim:
"Another good one is the B214ST on the NW Shelf of Oz. One engine oversped just after rotation off the rig, eng out light and audio illuminated (although eng had not failed) and, in accordance with their training, they reacted to the audio straight away by lowering the lever and causing the eng to reach the overspeed limit and shutdown leaving them with a real OEI situation that they had alreay set themselves up for (and a successful ditching)."
Point #1: eng out light and audio illuminated. Not so. Eng out warnings are predicated normally on low N1. This was never the case and no eng out warning was ever noticed by either pilot.
Point #2: Reacted to the audio. What audio? The HIGH RRPM has no audio in a Bell medium. It is probably being aware of this single fact alone that would give you the correct diagnosis.
I see by your previous posts that you are a 212 driver. From your claims above you would have been sitting in the Timor Sea as well scratching your head. I would strongly suggest you go through a high side governor failure on the 212 in the flight manual and just think through the indications you would have. When you get that sorted go back to whoever gave you a type endorsement and ask them maybe they are ignorant of the facts as well. Remember the Aussie airforce 707 incident. The indications of a high side failure will probably be an increase in RRPM possibly followed by a RPM light and NO audio - depending on the remaining power available before the N1 limit was reached. There will be no indication of an engine "failure" all you have is a governor failure. The needles N1, ITT, Q etc will indicate like a failure yet there is no "engine out" indication. The one that "looks" like it's failed will be the good one. My read of it would be to contain the high RRPM with increased collective if you can. What you would like to avoid is an overspeed of N2 and subsequent shutdown. The torque fluctuation from the overpeeding engine and then the remaining good engine trying to pick things up will certainly brighten your footwork. This is just a dopey old flyweight system that is definitely not pro-active like modern electronic systems.
After you have the Nr contained you can make an assessment of what has gone wrong and remedy because hopefully you have been through the scenario already with the indications as described.
I think London cabbies call this "The Knowledge" and in the Aussie Airforce incident the "knowledge" was not on board at the time.