OK - Treating Shepherd after the shooting is entirely consistent with both the tactical situation and Brown’s explicit orders. The necessity was to neutralize the immediate threat to the perimeter: Shepherd approached the bridge, was ordered to halt, refused, and turned away—creating a clear risk of alerting the town while the raiders were still consolidating their hold on the arsenal and bridges. Once he was down/no longer an active threat, there was no further military imperative to kill him.
Brown had repeatedly instructed his men to avoid unnecessary loss of life (“make no push to take life where it can be avoided”). Allowing a local doc to treat Shepherd, expressing regret, and later permitting the train to depart all align with that directive and with basic principles of restraint once a threat is neutralized.
In military terms, this is standard:
1-you stop the incursion
2-you provide care to the wounded
It does not retroactively make the initial shot “unthinking panic”—it shows disciplined application of force followed by adherence to orders against gratuitous violence. Brown’s overall conduct during the raid supports this distinction.