Disrespected while correcting a Soldier, how would you handle this situation?

Suggest you review UCMJ
Article 91: Insubordinate conduct toward warrant officer, NCO, or PO

It is extremely difficult or even impossible to "armchair quarterback" this situation without having been there.... this is your retelling the event ....and it is your perception of events.... that having been said.....there are some points that can be made....
FIRST You were RIGHT..... the problem is how to handle the situation
SECOND I think there was more going on here than just the "wrong uniform".....I think the individual you were correcting "MAY" ? have an issue taking orders / corrective action from a female. Male ego, sadly not an usual situation.
THIRD He had to be corrected but I think you should have remembered "Punish (correct) in private; praise in public" When you "attack'' in public you create a battlefield where it is you against him.... and you can not afford to lose.....so you need to be sure have the power and support to win.... not just rank
FOURTH Technique.....do not know the complete context....but the civilian reference "yelling" ....NEVER raise your voice.... to many it signals loss of control.... a whisper can be far more threatening that a scream.... I might also have started by saying something like...??... " Why have you chosen to disobey the judges order by wearing the wrong uniform?''
FINALLY You have no control over a civilian ..... He was WRONG..... but what do you do about it....?? Possibly I would do something like talking to him in private and saying something like " You are an experienced ex-serviceman and you obviously feel I handled this wrong.....so how would you have handled the situation?" ....I also would have said something like ..."If you were in my place....the trooper disobeyed orders.....disrespected your rank / authority..... would not take correction ....and then I interrupted you and told you in front of him....go yell at him someplace else....HOW WOULD YOU FEEL.....?.... As a veteran I respect,... I sort of expected your help not you making things worse for me...... BTW I would not yell at the civilian...... and trying to get him "disciplined would also be a mistake ..... even if you won the victory would be Pryyrhic

Talk to him/her like they are a human being first off.... Barking orders with someone getting court-martialed obviously isn't gonna work. Use your brain housing group and be more tactful. You are letting your rank define your power with a person who cares nothing of it as far as the civilian is concerned, so again talk to them like they are a human being and you might have gotten a leg up.

I would have given him a direct order to, Go back and change uniform and report back to me, now!"

Throat stomp engaged

What was the outcome you were expecting. There comes a time when correcting a soldier will do literally nothing, and this seems like it's one of those times.

It also sounds as if you were making a scene in a courthouse so that may have been the reason the civilian response.

Don't take this the wrong way, but the way I read this is that you were purposely making a scene in an attempt to embarrass the soldier. There are many other ways to get your point across and due to the lack of information provided by you it certainly sounds like what I just stated.

Feel free to flame me, but unless your provide more information, and someone who was present that can verify the story, I'll keep backing this statement. Somehow we all forget that it's innocent until proven guilty, not guilty because someone of higher rank said so.

Actually, I would have written a statement as well as having the paralegal write one and amended charges to include insubordination and refusal to obey a direct order. But that's just me.

I've seen some responses that say "I'd have smoked him, I'd have made him do this or that." This guy had no fucks left to give. He's at a court martial, that should pretty much answer things. There's no reason to get into a power struggle if the person doesn't care about rank, discipline, and respect. You did the right thing by walking away to cool off, no point jeopardizing your career for a scumbag. As for the civilian... again, lots of folks saying they'd "go drill sgt on her, tell her not to interfere," and on and on with a bunch of bs answers. Here's the deal. You think she should have understood what you were doing because she wore the uniform? Ok. How long was she in? What rank was she when she got out? How long had she been out? What kind of office was it? There's a lot of this we don't know about the situation. If she got out, let's say as a Col. from legal, 1) all you dumb asses saying you'd jump her shit, she may have jumped back, or worse, she may have called the cops and said you're making threats. 2) she might have come telling you to take the yelling somewhere else to preempt you getting your ass in a sling with someone else in her office. 3) she may have seen a lot of those disrespect situations, and just been over it, and wanted some quiet so she could make her spreadsheets. Who knows. Civilian office jobs and military counseling and corrections don't seamlessly intersect, two completely different worlds and ways of doing things. I'd say, you need to respect her (and others) workplace just as much as you would like her to respect the need, and your right, to correct a soldier. Either way, as long as you walked away and learned something, you did good.

Amber, if this individual was not the accused, who was he?
If he were a witness, I would simply prepare my statement for counsel for both sides as potential impeachment evidence and take the entire incident back to his COC. With regards to the civilian, I would simply remind her of how the military works because she had apparently forgotten. Remember, she USED to be a Captain. You can't tell her off, but she does not enjoy the protections granted to officers under the UCMJ.
If the individual is a bailiff, I would work with the CR and counsel for both sides to schedule and R.C.M. 802 to discuss the merits of a contempt of court hearing. Then, turn him over to the COC.

If that doesn't give you satisfaction, get a table, 30 feet of rope, 2 five-gallon water cans, and a burlap bag.

I believe that SSG Mc Lamb did as good a job as the limitations placed on her allowed her to do, absent putting the soldier in question in both handcuffs and leg restraints to make the point that he's still subject to UCMJ proceedings for his actions, or lack thereof. What I find difficult to fathom about this whole situation is that his CoC didn't have him in the proper uniform to report to the court in the first place, they do, after all, have to be informed of the change to the soldier's "place of duty", the time frame involved, and the proper uniform for the SM to be wearing upon reporting to that place of duty. This SM's entire local CoC needs/needed to have their asses "jacked up" for their failure/s with regard to this SM's failing to comply with orders that they were made aware of in advance.