[mindslight]

I would honestly be interested in the first 0.5-10 minutes of your leprechaun theory (depending on beer consumption, and if I'd heard similar things before), then I would try to change the subject and hope that there was more to you. And the same would apply if you were to go on a rant about how people who take joy in the idea of leprechauns are positively stupid.

It's not that true/false are equally credible, it's that assertion of either one starts off utterly non-credible. Extraordinary claims require extraordinary evidence and all that. This applies to proving the existence of leprechauns. But it also applies to positively disproving the existence of (a specific definition of) leprechauns, especially with the goal of using that result to imply something else.

Insisting the definitiveness of either take on a middleground is akin to rooting for sports teams (not that that isn't fun, but don't think you're helping spread truth).