This "man" had positioned his vehicle and thus the cars behind it in a confusing fashion originally thus causing my error.
Sounds like you still hold him responsible for your
error. And why is he referred to as a "man"? Was he a woman disguised as a man, or do you still think of him as less than a man? For all you know, he could have had a wife and five kids in his mini-van, and you were one harsh word away from ending his life and adversely affecting all of their lives.
From your story, he had no weapon, and I didn't read one thing that indicated that he did anything threatening other than looking displeased (for which you can hardly blame him). With no other way to let you know, he exited his car to tell you that you cut the line in front of him and a bunch of others who were waiting. As a result, you end up congratulating yourself for not shooting him. There's something wrong with this picture...