Wanna go further?
Snell doesn't batch test helmets. So, you can send in twelve helmets, I'm just pulling a number, and all the helmets that are produced get the sticker, regardless of the variations in production during many runs going through thousands of helmets.
Regardless, both HJC helmets carry a Snell sticker. There are other standards too, BSI/EU and DOT, but neither has been proven to be better than another.
Many different ways to fill the bag with ten or thirty pounds. Regardless, the said HJC helmet, which carries both DOT and Snell standards, similar to other low cost brands and models and higher cost brands and models, are not the focus of a simple safety concern based on outright experiences of a safety crew in a racing organization...too many concussions for the get off...and others on this thread are even expressing a potential problem.
I don't recognize any way to completely eliminate concussions through helmet technology. Give a person a hard enough impact, and one can get it.
Is it the standards fault? Is it a fault in the specific production of a manufacturers helmet that is not batch tested? The batch testing might be more telling.