Good observation. Going from memory, either all or most of Clough42 test filaments were either carbon fiber or glass fiber, which might have also helped by being warp resistant. Probably a warp is what induces the adhesion failure, so he was double protected by virtue of his filament choices.
In the case of CNC Kitchen, the Mandalorean head he printed on H2D had initial adhesion, but on another thread I posted that one of his support trees “disappeared” during the print, probably from a warp induced lack of adhesion: The wait ends on March 25! 🚀 - #961 by NeverDie The result was a deformed chin, because there was no tree to support it. In that particular instance, CNC kitchen glossed over it and made no mention of it, but by playing the youtube back in slow motion we found out what happened.