It was someone different who said that. There's a chance the authors might've gotten some claim wrong because their maths and/or methodology is shoddy but it's a large and diverse set of authors so that's unlikely. Fraud in CS empirics is generally unheard of, I mean what are you going to do when challenged, claim that the dog ate the program you ran to generate the data? There's shenanigans about the equivalent of p-hacking especially from papers from commercial actors trying to sell stuff but that's not the case here, either.

CS academics generally submit papers to journals more because of publish or perish than the additional value formal peer review offers. It's on the internet, after all. By all means, if you spot something in the paper that's wrong then be right on the internet.