In my opinion, this was his mistake. He should never have left, but should have resolved the dispute right then and there. By leaving so that he could simmer down, he instead had a chance to fume at the needless humiliation he had suffered at the hands of a worthless little punk. It ate at him quickly, and he could not let it rest. He lost his temper. I think he wanted to beat the punk up - - teach him a lesson real good - - but I don't believe he wanted to kill him. The punk ended up dead, and 6 to 10 is probably about right.
Bravo to our system of justice.