I know, and I do not like it either. But by pleading guilty, Lt. Col. Lakin showed that he agreed with the government's assertion that 0bama is eligible to serve as president and that he was wrong to question that assertion. Even if he wanted to appeal this guilty plea, it is going to be next to impossible to do so.
Had he gone to trial instead, the government would be obligated to show its evidence, and even if the government somehow got out of that obligation, that action too could be appealed.
The way I see it, Lt. Col. Lakin chose to pretty much end his military career by challenging his orders on eligibility grounds. If he was so willing to make himself the test case, then why not at least go all the way and force the government to show its cards?
Copping a plea is only what you do when you know the government can nail your rear end to the wall in court, you want a lenient sentence, and the prosecutor wants an unappealable conviction.
He wasn't the first. Freeper, roaddog727, challenged Bowbama's eligibity a couple of years ago.