Disagreements between customers and vendors happen, but hopefully cooler heads eventually prevail, and nobody gets hurt.
That wasn't the case at a hot dog food cart in Sweden, as this Worldstar video shows an older gentleman behind the counter punch a customer right in the forehead after a heated exchange.
The argument itself wasn't what escalated things, it was only after the customer leaned over the counter and slowly spit out what he was eating, that the vendor lost his cool. Before any of the masticated mess could reach the food, the punch was thrown and the cook wiped off his counter.
While that's not exactly the kind of customer service you want to see at any establishment, that customer was being a dick, and deserved to get punched out. It even looked like his lady friend was recording the whole thing, anticipating that he would do something stupid.
No one seemed to be seriously hurt. The patron walked away with his consciousness in tact, and everyone went about their day.