I think you need to get some facts right to start with. I was at the meeting as well as at the lecture. The youtube video is not of the actual presentation at the meeting, but recorded at some other time. Total registrations for the meeting were around 460 (including day registrations and some partners). On any given day, there were around 400 present, of which about 200 were from Australia. These were a mix of military, DAMEs (and equivalent), engineers, nurses, researchers, pilots, adventurers, and a small number of regulators (including from CASA).
Dr Pape's 10 min talk was well delivered, but had marginal scientific relevance in terms of statistical significance (as is the case with many low-number case studies). The feeling I got was that Dr Pape was being a little disingenuous in his repeated line that these pilots were being disadvantaged by their inability to name colours. The main function of the test is not the naming of colours, but rather the ability to discriminate between colours. There was a bit too much "used car salesman" in it for me.
There was some broad agreement that the tower signal gun test was of little relevance in modern aviation.
It certainly promted significant discussion, especially the apparent discrepancy between the ability of pilots to fly in command of aircraft of certain categories. The feeling I got from those I spoke to (including a number of international delegates), was that this discrepancy would be better resolved by tightening the current standard rather than relaxing it. This was due to the complex, and often relatively subtle use of colour in modern cockpits (it is no longer a red/green/white environment).