I think some architects share common design traits. That wouldn't be a surprise. You can see Flynn in Ross or Ross in Flynn. I suppose the same is true for Park. I know that Concord was thought to be a Ross because it looked like a Ross. That was proved untrue when the Flynn plans were brought to light.
Ron Prichard is an excellent researcher and a superb architect. Without knowing the specific features that Ron was referring to, this remains a non-starter discussion. I don't know what Ron said, I don't know what he was told (a Philmont member is the biggest supporter of crediting Flynn).
I am certain Ron wouldn't want to cause a controversy at the Flynn Cup at Philmont but it is hard to say what the dynamics were. I don't know what to say. I think the opportunity existed for you to politely question the matter. You decided not to then, it may be that you do so in private now.
In any case, Ron's talk, if as described, does not change the fact that there is no evidence linking Flynn to Philmont, whether a photo of Wm Gordon on opening day exists or not. That is the issue at hand.