Thanks for your replies. To answer the questions, he was an adult when this happened, and he's been to the US once on an ESTA, last year. He answered no to the question @Redro posted because he saw the small fine he had to pay as comparable to a speeding ticket. He's quite fuzzy on the details because it happened so long ago, which is why we're going to get a subject access request. We can avoid having him enter on ESTA again while we get some clarification.
I don't believe I qualify for DCF, I don't have a job offer or anything, but will look into it.