and it marks the first time Archer just straight up murders people in order to protect his ship and crew -- a great foreshadowing of his actions in the Expanse.
I've been known to be harsh on some of Archer's more boneheaded choices, but even I'd say murder is a stretch. The guy's defending his ship against a force with lethal intent. Sure they were some of his own people, but that's what makes the Borg an insidious force.. they do turn your allies against you.
Some of his choices in the Expanse... justified or not... were more morally ambiguous.