Lowering the lever first will NEVER be a bad thing (unless you are in a low hover - the exception to prove the rule) because it will prevent further Nr Decay.
Coming from a technical side I want to refrain from commenting anything from a piloting perspective.
However, from a pure technical perspective that is not entirely precise, it will not prevent NR decay but it will reduce it.
If done very violently at a very high forward speed you might even be able to achieve a rotor stall when keeping the cyclic forward.
That said no one would do that in reality.
However, maintaining RRPM Comes from the tilted back (read flared) rotor disc vs. the flight path during autorotation. However a tilted back rotor disc will slow down the Helicopter. This has to be balanced in order to maintain the necessary airspeed and thus airflow through the disc. Lowering collective will do that. The sequence in which you establish this stable condition won't matter unless it takes too much time.
In which case both ways if done to the extreme (Only flare without lowering collective as well as only lowering collective without relaxing cyclic) would render you equally dead.
The strange thing in this discussion is that when reading carefully everybody here seems to have the same actions in mind. It's just whereupon the emphasis is laid where the difference lies.
All the more unfortunate that such a harsh discussion has ensued. As (primarily) an interested Reader I hope the emotions calm down a bit and the interesting discussion can continue.
@John Dixson: Thanks for the explanation! I found the discussion about technical limits interesting and therefore thank you for your contribution but I also understand concerns that this might be taken by some out of context (which I hope really doesn't happen).
Any such values will only apply for a certain situation and numbers will vary significantly depending on Type (I would expect see a drastic difference between a lightly loaded S-70 and an R-22 close to MAUW), Weight and circumstances.