I would think that in addition to reversing the suspension, they would also want to prove Braun's innocence. They haven't put forward any legit reasons/excuses for the failed test. They haven't questioned or addressed the fact that synthetic testosterone was in Braun's urine.
I would argue that is a job for Braun's PR people, not his attorneys.
Braun said what he had too in that on-the-field presser, you are either going to believe him or not (or in my case, not sure). That's really all he can do, you can't retake the test from October at this point.
Many other baseball players have claimed what Braun did in that the test results were invalid, Braun's just has more name recognition than these guys and this definitely helped him.