Hoppit, I don't think anyone is trivialising this report, as you say there will be a lot of interesting stuff if its well written (though some recent AAIB reports seem to be written by people who don't understand helicopters). I totally agree that dual rating L2 and 225 (esp during the same duty period, if that's true?) is not best practice. Unfortunately for the time being its quite legal.
I was dual rated on L and L2 for a while, didn't find that too much of a problem since they are quite different beasts. Then I was dual rated on L2 and 225 for a brief period, I found that much more of a problem, so similar and yet so different. The probability of pressing the right FADEC button under the collective in the event of an engine failure was minimal, and operating techniques to get the best out of the automation are completely different.
HC