From the 2012 Manual for Courts-Martial (CLAMO).

Negligent Homicide

60. Article 134—General article

a. Text of statute.

Though not specifically mentioned in this chapter, all disorders and neglects to the prejudice of good order and discipline in the armed forces, all conduct of a nature to bring discredit upon the armed forces, and crimes and offenses not capital, of which persons subject to this chapter may be guilty, shall be taken cognizance of by a general, special, or summary court-martial, according to the nature and degree of the offense, and shall be punished at the discretion of that court.
85. Article 134—(Homicide, negligent)

a. Text of statute. See paragraph 60.

b. Elements.

(1) That a certain person is dead;

(2) That this death resulted from the act or failure to act of the accused;

(3) That the killing by the accused was unlawful;

(4) That the act or failure to act of the accused which caused the death amounted to simple negligence; and

(5) That, under the circumstances, the conduct of the accused was to the prejudice of good order and discipline in the armed forces or was of a nature to bring discredit upon the armed forces.

c. Explanation.

(1) Nature of offense. Negligent homicide is any unlawful homicide which is the result of simple negligence. An intent to kill or injure is not required.

(2) Simple negligence. Simple negligence is the absence of due care, that is, an act or omission of a person who is under a duty to use due care which exhibits a lack of that degree of care of the safety of others which a reasonably careful person would have exercised under the same or similar circumstances. Simple negligence is a lesser degree of carelessness than culpable negligence. See paragraph 44c(2)(a).

d. Lesser included offenses. None

e . Maximum punishment. Dishonorable discharge, forfeiture of all pay and allowances, and confinement for 3 years.
JMM emphasis added - see defenses below (Justification and Self-Defense).

Negligent Dereliction of Duty

16. Article 92—Failure to obey order or regulation

a. Text of statute.
Any person subject to this chapter who—
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(3) is derelict in the performance of his duties; shall be punished as a court-martial may direct.

b. Elements.
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(3) Dereliction in the performance of duties.

(a) That the accused had certain duties;

(b ) That the accused knew or reasonably should have known of the duties; and

(c) That the accused was (willfully) (through neglect or culpable inefficiency) derelict in the performance of those duties.

c. Explanation.
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(3) Dereliction in the performance of duties.

(a) Duty. A duty may be imposed by treaty, statute, regulation, lawful order, standard operating procedure, or custom of the service.

(b ) Knowledge. Actual knowledge of duties may be proved by circumstantial evidence. Actual knowledge need not be shown if the individual reasonably should have known of the duties. This may be demonstrated by regulations, training or operating manuals, customs of the service, academic literature or testimony, testimony of persons who have held similar or superior positions, or similar evidence.

(c) Derelict. A person is derelict in the performance of duties when that person willfully or negligently fails to perform that person’s duties or when that person performs them in a culpably inefficient manner. “Willfully ” means intentionally. It refers to the doing of an act knowingly and purposely, specifically intending the natural and probable consequences of the act. “Negligently” means an act or omission of a person who is under a duty to use due care which exhibits a lack of that degree of care which a reasonably prudent person would have exercised under the same or similar circumstances. “Culpable inefficiency” is inefficiency for which there is no reasonable or just excuse.

(d) Ineptitude. A person is not derelict in the performance of duties if the failure to perform those duties is caused by ineptitude rather than by willfulness, negligence, or culpable inefficiency, and may not be charged under this article, or otherwise punished. For example, a recruit who has tried earnestly during rifle training and throughout record firing is not derelict in the performance of duties if the recruit fails to qualify with the weapon.

d. Lesser included offense. Article 80—attempts

e. Maximum punishment.
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(3) Dereliction in the performance of duties.

(A) Through neglect or culpable inefficiency. Forfeiture of two-thirds pay per month for 3 months and confinement for 3 months.
Defenses

Rule 916. Defenses

(a) In general. As used in this rule, “defenses” includes any special defense which, although not denying that the accused committed the objective acts constituting the offense charged, denies, wholly or partially, criminal responsibility for those acts.
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(b) Burden of proof.

(1) General rule. Except as listed below in paragraphs (2), (3), and (4) [JMM: not applicable here], the prosecution shall have the burden of proving beyond a reasonable doubt that the defense did not exist.
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(c) Justification. A death, injury, or other act caused or done in the proper performance of a legal duty is justified and not unlawful.

Discussion

The duty may be imposed by statute, regulation, or order. For example, the use of force by a law enforcement officer when reasonably necessary in the proper execution of a lawful apprehension is justified because the duty to apprehend is imposed by lawful authority. Also, killing an enemy combatant in battle is justified.
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(e) Self-defense.

(1) Homicide or assault cases involving deadly force. It is a defense to a homicide, assault involving deadly force, or battery involving deadly force that the accused:

(A) Apprehended, on reasonable grounds, that death or grievous bodily harm was about to be inflicted wrongfully on the accused; and

(B) Believed that the force the accused used was necessary for protection against death or grievous bodily harm.

Discussion

The words “involving deadly force” described the factual circumstances of the case, not specific assault offenses. If the accused is charged with simple assault, battery or any form of aggravated assault, or if simple assault, battery or any form of aggravated assault is in issue as a lesser included offense, the accused may rely on this subsection if the test specified in subsections (A) and (B) is satisfied.

The test for the first element of self-defense is objective. Thus, the accused’s apprehension of death or grievous bodily harm must have been one which a reasonable, prudent person would have held under the circumstances. Because this test is objective, such matters as intoxication or emotional instability of the accused are irrelevant. On the other hand, such matters as the relative height, weight, and general build of the accused and the alleged victim, and the possibility of safe retreat are ordinarily among the circumstances which should be considered in determining the reasonableness of the apprehension of death or grievous bodily harm.

The test for the second element is entirely subjective. The accused is not objectively limited to the use of reasonable force. Accordingly, such matters as the accused’s emotional control, education, and intelligence are relevant in determining the accused’s actual belief as to the force necessary to repel the attack.
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(5) Defense of another. The principles of self-defense under subsection (e)(1) through (4) of this rule apply to defense of another. It is a defense to homicide, attempted homicide, assault with intent to kill, or any assault under Article 90, 91, or 128 that the accused acted in defense of another, provided that the accused may not use more force than the person defended was lawfully entitled to use under the circumstances.

Discussion

The accused acts at the accused’s peril when defending another. Thus, if the accused goes to the aid of an apparent assault victim, the accused is guilty of any assault the accused commits on the apparent assailant if, unbeknownst to the accused, the apparent victim was in fact the aggressor and not entitled to use self-defense.
Regards

Mike