You said something was conclusive proof because it fit into the narrative you have built for yourself around the club, the owners, everything.
Yes, when people are so entrenched in their views about something, everything they see, hear, feel, read, and experience is related back to their 'truth' about the world and reinforces their worldview.
Then, they project that worldview onto others, claiming that their single truth is the right one and paints anyone else who doesnt share it as the enemy, as having the polar opposite view to them, despite it actually being nuanced.... because they feel so challenged by their world view maybe not being as clear cut as they think.
Call it confirmation bias, motivated reasoning, belief perseverance - whatever you want - this dynamic is well explained and has been for many years.
And of course, you won't accept it or care, and that's fine. It's just fascinating seeing it in action.