I was at the produce aisle in the supermarket buying potatoes when an old man pulled up to one of the digital scales with a shopping cart laden with the cheapest processed meatballs you can get. He then proceeded to weigh every single container, either to make sure they contained the promised 360 grams or hoping some of the boxes had extra meatballs in them
Stuff like this isn’t usually packed strictly by weight. It’s packed by “volume that probably weighs about the right amount based on average density”. In most places there is a legally allowed +/- % to enable manufacturers to churn out slop as quickly and efficiently as possible. They’re supposed to have a QA department that makes sure it averages out over a large number of packages, but in practice who knows. Regulators are usually too busy / understaffed / underfunded to police that kind of shit proactively anyway, and even if they do get caught, the fine is probably less than the savings they’d get from shorting customers en masse. The manufacturer will absolutely have done the math on that.
So fuckit, more power to him.