Well, I seem to recall that the experts told us that a two week shutdown would solve the problem. Then they said you get the China Death Bug by touching a hard surface that was contaminated. Then that a mask, no make that no mask, no make that 2 masks is the cure.Now hold on a second here. While it may not be an official "super spreader event", its quite obvious that gathering 400,000 people into one location during a pandemic caused by respiration will in fact cause spreading. That is not a lie. It is simple physics. If no one there is talking, sneezing, laughing, or even breathing, then we can say it was not an issue. But having that many people together for 10 days performing daily bodily functions certainly was not a good idea.
The article you attached does not account for the exponential spread post-mortem. The R-not number of covid-19 is between 3-4 so every single case spawned from that needs to be multiplied again, and again, and again unless mitigation measures are being followed (which we all know is not being done in South Dakota).
The best evidence we have, unfortunately, is largely anecdotal. Floridians are NOT dying at higher rates than Draconian New York. Neither are South Dakotans. These things, we do know.
Doc Fauci and hosts of other "experts" have studied the bejesus out of this thing, ad nauseum, for a year - and still don't know squat. I don't think anyone else (at least, outside of China) does either.