But we must also recognize a difference in degree. In a competition where the US has no official influence over the result, there has to be a huge conspiracy to affect which algorithm is chosen. But in the competition which actually happened, they may potentially just need a single plant on one of the strong teams, and if that plant is successful in introducing subtle brokenness into the algorithm without anyone noticing, the NIST can just declare that team's algorithm as the winner.
I think it's perfectly reasonable to dismiss this possibility. I also think it's reasonable to recognize the extreme untrustworthiness of the NIST and decide to not trust them if there's even a conceivable way that they might've messed with the outcome of their competition. I really can't know what the right choice is.