Adrian,
I think it's safe to say the RNAS used the same system as the RFC.
An RNAS claim would be vetted by the squadron CO then passed to Wing and on up to RNAS HQ. At each stage the evidence from other parties would be assessed and a judgement made.
When an RNAS squadron was attached to the RFC, as was the case with the "Detached Squadron" in 1916 (what everyone calls Naval 8 though it wasn't), Naval 3, Naval 1, Naval 6, Naval 8, Naval 10 and Naval 9 then they had to follow the RFC regime exactly - Squadron CO, RFC Wing, RFC Brigade, and finally RFC HQ.
I know many might say that I'm biased, but my gut feeling is that in most circumstances, the RNAS claims were more realistic than those submitted by the RFC. I obviously cannot prove this, and can't be bothered to try!!!