My statement is true, because there is some evidence that it can be done. I did not say that everyone can see said results at all times.This isn't yet the case, as has been discussed on that thread there were a couple of JL flights which popped up upon searching the OP's routes.
No other person, nor the OP has been able to see those flights again when searching on QF (even on the same route).
More the likely they were doing some testing for an impending rollout, which was mentioned last year as JL rolled out Amadeus.
You don't know if no other person could see those flights again - maybe some did and have not reported it, or are not AFF members.
There could be many explanations why some can see and some cannot (selective availability, etc) - the bottom line is you lack that knowledge. For the most part, the rest of us do, too. Belief is not the same as knowledge.
I've found the JL website to be accurate for international flight availability using QFF.