Let’s say I’m ~80% sure that she doped, but there’s at least a 20% chance that the test that USATF uses are noisy or too sensitive or something like that.
With those beliefs, I think a 4-year ban is appropriate and she is welcome to compete. I won’t cheer for her but I wouldn’t boo her either or anything like that. If I were 100% sure she had doped, I’d say lifetime ban.
(Shelby does not need to be a hero for us to believe that the anti-doping monitors of track are incompetent or corrupt. We also don’t need a specific hypothesis about how they messed up to think that it’s at 20% likely that they did.)