There was a situation that happened at last years NATs involving Paul Walker's first flight in the Open Finals. If I recall the events correctly, Paul had just finished his flight and his helper who was attending to the plane had not secured or "disarmed" the plane by pulling his arming plug. By the time his helper disarmed the plane, Paul inadvertently switched the handle from his right hand to his left hand "before" his helper disarmed the plane. This resulted in Paul receiving a 0 score for his first flight. Is this a correct interpretation of this rule?
Not of the current rule book version. It may well be a correct implication of the special NATs rule regarding this (that predated the official one). The initial version (before 2011) was that removing the safety thong before disarming the model was not allowed. I intentionally removed that based on comments here, and the altered version is the one in the rule book.
It's OK to have different rules for the NATs, and I have to admit I wasn't paying any attention to what was briefed at the pilot's meeting last year, so I don't know.
The reasoning behind the rule book version was that we want single-failure safety, that is, if it starts unexpectedly, someone also has to drop the handle before it is unsafe. So just holding the handle is good enough, including handing it off to your helper while you go to disarm the airplane.
Requiring the safety thong, too, is dual-failure tolerant, because if the airplane starts unexpectedly AND you drop the handle (two failures, not one) then you still have the thong backing you up. It's OK to be safer, but this does exceed the levels of margin/tolerance we use for everything else in stunt (like the pull test) and does cause minor operational restrictions like not being able to hand off your handle to someone else.
If it had been me, and I hadn't paid attention (which is shame on me), I would have expected the rule book version, and may have gotten burned on the same issue were I flying electric.
I don't know what version will be used, but fortunately, we know the CD!
Brett