Evidence is presented by both sides in a Court Martial trial. The UCMJ specifically states that the accused must be allowed to present his defense. The hitch is that the Military Judge, and not the Court, gets to decide if evidence is "relevant", before allowing it to be presented.
And I predict that the judge will rule that the issue of Obama’s eligibility is not relevant and will proceed to trial. I’m rather amazed that there are people advising this guy that he has even a ghost of a chance.