Hunger, fatigue, general negative state of mind maybe.
This particular guy was a contract worker who came in for an early lunch, so I assume they’d been working for some hours before they came in.
Generally the blue collar worker dudes and the after church crowd were the meanest with the least tolerance for mistakes.
Username checks out.
Sadly the ‘factory farm’ dairy industry probably won’t follow the proper hygiene you’re referring to, and I’d imagine that the current administration would be more interested in reducing the regulations that would force proper hygiene than increase them.