What would I expect, expecting some actual ways one can defuse a situation. You are talking into  air here. As a nurse since 1972 I have confronted many angry and hostile people at my job and you learn how to defuse the situation and I will tell you that it is easily done. The person pumping the gas could have started with, " I see that you are angry, I am very sorry this got out of hand so fast, I apologize, man, no harm meant." 
And surprising, many times it leads to a male "ritual" called a handshake. I suppose that would not satisfy a man whose brain hangs from his lower abdomen. By the way my "dialogue" is not made up. I heard this actually said by 2 servicemen who got into a Pi**ing contest and one of them said this to the other one thus defusing the situation. The truth is I have been around all kinds of males all my life, there is no excuse for anyone not to be able to handle themselves in a public place. My husband will tell you that to.