That’s a very unfair position to take when dealing with secret agencies who try very hard to obfuscate this stuff - it is hard to provide evidence for in the moment.
The government has intentionally acted to weaken DES, standardized Dual_EC_DRBG, performed subtle subterfuge through interfering how NIST operates to inject weaknesses and vulnerabilities, trying to weaken SSL and IPSec, 4G smartphone encryption.
These are all documented examples of the NSA engaging in bad faith. So whether or not it is happening in this particular case, there’s now just zero trust in the institutions acting in good faith. And given it took decades for the actions to come out after they were taken, how do you expect someone to answer your request to present evidence there’s anything nefarious happening now?
Anyway, that’s what I think a fleshed out argument would look like
It's a simple question. I'm not asking anybody to prove anything. I'm literally asking: propose the PQC standard IETF could have subverted, and give a sketch of how they could have done it. The bar is merely "plausibility". I'm not asking whether NSA has subverted standards before; obviously they have.
NSA, by the way, rescued DES from differential cryptography, the core mechanism by which block ciphers and hash functions have been attacked ever since.