What are some Counseling Form Details that void a Counseling statement?

A counselling form is merely a written record of a conversation. It is preferred that the counselling forms be signed by both parties on the same day, but so e times that can't happen. They can't be back dated, however. Recommending UCMJ, while a tad vague but at the same time blunt, is a Plan of Action. This is a perfect opportunity for you to research the Regs of Counselling to better educate yourself so you'll have a better understanding of what is right and what is wrong.....and so that you can also teach those that come after you.

There are no details that "void" a counseling.
A counseling form is just a written record of the conversation that took place between the two names on the form.

Nothing voids a counseling, and signing doesn't always happen on the same day but is preferred and so long as it isn't backdated (which I have seen) it's good to go, but if it gets kicked back from JAG for not having enough details (5W's, etc.) that NCO is going to get a word or two from the 1SG or CSM.

While your NCO can recommend UCMJ they have no authority whatsoever in initiating it, that's commanders territory to initiate and JAG's to process. It is not uncommon for a commander to decline the request or for the 1SG/CSM to come in and recommend alternative methods of retraining and counseling, especially if JAG kicks back the supporting documents. Which is why NCO's shouldn't threaten UCMJ action just to get a Soldier in line, since initiating it is not in their purview.

When I have taught and assisted with legal LPD's on counseling to NCO's and how they relate to UCMJ we recommend an actual plan to retrain the troop before just recommending UCMJ williy nilly and remind commanders that 600-20, 4-6 states Military authority is exercised promptly, firmly, courteously and fairly. Commanders should consider administrative corrective measures before deciding to impose nonjudicial punishment.

That said you should not count on this to happen and take the recommendation seriously, if you screwed up work on a plan to fix it with your NCO. Counting on some obscure technicality is going to set you up for failure.

MSG (Join to see) is right, use this as an opportunity to research the reg and learn.