Won't post all pages but here it is with no reference to firearms.( See HRS 703)
Hawaii's Good Samaritan Laws
HRS § 663-1.5:
Exception to liability.
Check out HRS 663-1.6 Duty to Assist
Section 663-1.6 - Duty to assist person at the scene of a crime who knows that a victim of the crime is suffering from serious physical harm shall obtain or attempt to obtain aid from law enforcement or medical personnel if the person can do so without danger or peril to any person. Any person who violates this subsection is guilty of a petty misdemeanor.
(b) Any person who provides reasonable assistance in compliance with subsection (a) shall not be liable in civil damages unless the person's acts constitute gross negligence or wanton acts or omissions, or unless the person receives or expects to receive remuneration. Nothing contained in this subsection shall alter existing law with respect to tort liability of a physician licensed to practice under the laws of this State committed in the ordinary course of the physician's practice.
(c) Any person who fails to provide reasonable assistance in compliance with subsection (a) shall not be liable for any civil damages.
HRS § 663-1.6
L 1984, c 140, §1
Section imposes on the perpetrator of a crime a duty to obtain necessary medical aid for the victim.73 Haw. 236, 831 P.2d 924. Where evidence that child was a victim of battered child syndrome was relevant to show that child's death was not an accident, but the result of an intentional, knowing or reckless criminal act, giving rise to a duty on defendant's part to obtain medical care for child pursuant to this section, trial court did not err in admitting expert testimony that child was a victim of battered child syndrome.101 Haw. 332,68 P.3d 606. Applicable to the perpetrator of a crime. 8 H. App. 506, 810 P.2d 672.Wild. You have a duty to call EMS and/or the cops if you witness someone suffering from severe bodily injury.
Even the perp has a duty to call them after he beats/stabs/shoots you. Good luck with that.

Otherwise wise petty misdemeanor tack on charge. I’m sure they’re concerned about that.
Other than the modified “Castle Doctrine” what are the standards for use of deadly force outside the home premises under HRS ?
Looks like you can but still have a duty to retreat if possible outside the home or place of work.
§703-304 Use of force in self-protection. (1) Subject to the provisions of this section and of section 703-308, the use of force upon or toward another person is justifiable when the actor believes that such force is immediately necessary for the purpose of protecting himself against the use of unlawful force by the other person on the present occasion.
(2) The use of deadly force is justifiable under this section if the actor believes that deadly force is necessary to protect himself against death, serious bodily injury, kidnapping, rape, or forcible sodomy.
(3) Except as otherwise provided in subsections (4) and (5) of this section, a person employing protective force may estimate the necessity thereof under the circumstances as he believes them to be when the force is used without retreating, surrendering possession, doing any other act which he has no legal duty to do, or abstaining from any lawful action.
(4) The use of force is not justifiable under this section:
(a) To resist an arrest which the actor knows is being made by a law enforcement officer, although the arrest is unlawful; or
(b) To resist force used by the occupier or possessor of property or by another person on his behalf, where the actor knows that the person using the force is doing so under a claim of right to protect the property, except that this limitation shall not apply if:
(i) The actor is a public officer acting in the performance of his duties or a person lawfully assisting him therein or a person making or assisting in a lawful arrest; or
(ii) The actor believes that such force is necessary to protect himself against death or serious bodily injury.
(5) The use of deadly force is not justifiable under this section if:
(a) The actor, with the intent of causing death or serious bodily injury, provoked the use of force against himself in the same encounter; or
(b) The actor knows that he can avoid the necessity of using such force with complete safety by retreating or by surrendering possession of a thing to a person asserting a claim of right thereto or by complying with a demand that he abstain from any action which he has no duty to take, except that:
(i) The actor is not obliged to retreat from his dwelling or place of work, unless he was the initial aggressor or is assailed in his place of work by another person whose place of work the actor knows it to be; and
(ii) A public officer justified in using force in the performance of his duties, or a person justified in using force in his assistance or a person justified in using force in making an arrest or preventing an escape, is not obliged to desist from efforts to perform his duty, effect the arrest, or prevent the escape because of resistance or threatened resistance by or on behalf of the person against whom the action is directed.
(6) The justification afforded by this section extends to the use of confinement as protective force only if the actor takes all reasonable measures to terminate the confinement as soon as he knows that he safely can, unless the person confined has been arrested on a charge of crime. [L 1972, c 9, pt of §1; ree L 1975, c 163, §3; am L 2001, c 91, §4](Emphasis added)
Edit:
Can you protect someone else outside the home or work ?
Looks like can but you better have a damn good reason for it and have your ducks in a row when they arrest you.
Statute only refers to protect himself. And you have no legal duty to protect others but apparently you do have a legal duty to call the police.
Hope I’m reading this wrong and see the next post by CMO.
I am NOT a lawyer.