I dont care what race or religion are you - this is America, and you need to follow simple rules when you have a business.
The gas station owners and employee will be charged and easily lose this case, while costing them hundreds of thousands of dollars and the possible loss of the gas station. The simple thing was to take them out of the store and call the police, which would of come very quickly.
The problem is that these guys went way overboard, hitting woman, regardless of them screaming and yelling, and doing it OUTSIDE of the store. Big mistake, and a very stupid one at that. They are done. If the customers refused to leave the store, and started destroying the store, there still is no justification that you need to hit a person while behind held down. This is a cheap ass way.
Now, since the police was called, and now Exxon is involved, they are going to test the gas machines, and if they find out that they were spilling gas, or cheating the customers, huge fines and they are done anyway.
As for people outside the USA thinking this is the norm, jeez - get real. This incidents happen all the time, but keep in mind, 380 million people live in the US, and many areas, and most of us rarely ever see anything like this happen.