How would one write a proficiency and conduct rebuttal?

First and foremost, be able to articulate why you disagree with a specific point, and with the score in general. Things like PFT (1st class or 285+), Rifle Qual (Expert) all work in your favor on Pro.

Be able to cite examples of why it is incorrect using logic and reason, and avoid emotion where possible.

Remember that Proficiency & Conduct are Subjective to a degree, and without formal documentation, the range is significantly more narrow (4.0-5.0)

Use previous marks to establish a window. If you were at 4.5/4.5 previously, and the marks are being lowered to 4.0/4.0, request documentation to show when, where, and why the opinion has changed so drastically.

Remember, this is also your counselling session, and feedback is INVITED, and it is not necessarily a firm number until after the session. You may be able to present information that had been forgotten or poorly documented to raise the scores, like LoA, CerComs, etc.

Stick to the facts... Leave your feelings out of it, and take responsibility for what was your/their fault. Lastly don't blame other people.

The pro/con system in the Marine corps is flawed, I ha earn where a NCO or SNCO like a marine and give them inflated markings. So I would say stick to the facts, the corps has standards as long as that marine makes the standards then he is an average Marine.

In general? It is really have to be focused. For example you have to break down the merit of ones argument. Focus on challenging the logic or lack their of in each point of their argument. If you can show instances of where their points have led to failure in the the past then do so. Also in the end you should it all together so they could see the overall impact of their arguments. An example is when you make two small mistakes in succession the overall impact of both combined can be catastrophic.

You have had good advice. State facts. Document them when possible. Avoid argumentative statements.

There is no formal appeal or process of review for proficiency and conduct marks as outlined in the IRAM. I would suggest you try the informal resolution method with your chain of command and if the Marine is still unsatisfied with the response, he or she can always utilize his right to Request Mast.

I take a look at the whole Marine, from his off duty education to his involvement in the local community to his maturity on and off duty. Is he good at his job, do they exemplify JJDTIEBUCKLE. If they meet all of this than personal opinions should always be kept out of this process.