Helson were embarrassed by this a few times, which is one of the reasons that you can trust their ratings now...they get called out badly if they do pull a fast one
Helson depth-gate happened a long time before they started making brass watches.
Somebody had a Steel SD45 fail on them at 30m and then went about buying a bunch of their watches and pressure testing them. The results were not good. After that, Helson haven't put a foot wrong.
Cough cough... Bad timing?