I've watched a few episodes, and it seems like he only gets irate when people are just downright bad. It isn't like he'd go on a screaming match if you forgot to put the onion in a dish, but rather if you tried to lie to your customers (serving frozen food when it's described on the menu as "fresh") or doing things in a potentially dangerous way (increase the growth rate of bacteria, etc.). For example, I recall him getting on one restaurant about how they defrosted their meat in water versus naturally letting it thaw in a fridge. You would assume that cooking the meat kills the bacteria, but I guess it's still just unsanitary?