See, the thing is, you and Rojo are starting off from the false assumption that knowing something and believing something are necessarily two seperate things.
What is concrete evidence? Rekrunner says that even a doping positive isn't evidence of doping, and that a whereabouts failure certainly isn't. Peter Bol's lawyer says that an A-Sample positive is not evidence. Rojo doubts we 'know' that Shelby is truly guilty, even though she tested positive.
I 'know that the sun will set tonight, and that it will rise tomorrow. But I can't provide evidence that it will, because it hasn't happened yet. It's a justified true belief, as will be proven when the sun does set tonight, and rises again in the morning.