When you boil it all down, not all sides are created equal. And as has been pointed out a few times in this thread, there's plenty of transparency regarding the draft lottery. It is a perfectly ordinary claim to say that the NBA conducts a draft lottery in which outlier ping pong ball combinations occasionally result in less deserving teams winning the top few picks. It is quite an extraordinary claim to say that the NBA conducts a rigged lottery in which they've managed to hide their grift from all interested parties. Thus, it requires extraordinary evidence to mount a convincing defense of such a claim.
As an analogy, what you're saying is the burden of proof was on the viewers at home to substantiate that the moon landing was real. The science was vetted and transparently tested, and the evidence was ultimately placed right in front of the viewers' eyes to support the ordinary claim that man had walked on the moon. Extraordinary event, of course. But an ordinary claim. Whereas the production and subsequent cover-up necessary to fake such an event would represent an extraordinary claim that requires a much greater amount of evidence to prove that man had, in fact, not walked on the moon.
You're asking us not to believe our eyes, but instead to believe that a shadowy NBA cabal led by Adam Silver has managed to fool a wide variety of stakeholders about the veracity of the lottery results, putting the league's credibility and their entire business at risk. And for what, exactly? What's the upside of such a massive scam? A more engaged Dallas Mavericks fanbase? Some additional revenue in the pockets of the Mavs' owners?