Fascinating reading - bringing lots of memories back to my deck landings and also my EC135 flying.
Looking back at my time then, I clearly recall having to readjust my instrument scan from the centre of the 'hub' of instruments being the Main AI - to the centre being the RCDI. Anything greater than 300'/min caused alarm bells to ring, but I was so fixated on it - it rarely if ever happened as I became more experienced.
Also looking back over my career - I realise now, why I was so tired - mentally after night low level sorties, especially to decks - simply because of the sheer amount of concentration exerted.
Maybe (easy after the event) just maybe, the PiC dropped his guard and assumed the other pilot was experienced enough NOT to take his eye off the ball.
One of my most frequent mantras to all my students/co-pilots was always: NEVER EVER assume the pilot next to you knows what they are doing - especially the experienced ones!
Two seasoned vets unable to monitor and maintain a simple gentle RoD - how tragic is that eh?
Add HUET lack of currency and you have all the holes lined up.
I sincerely hope that someone out there will learn from this (and other accident reports) and live to see retirement.
RiP.