SecUnit would love to say that Heat started it, by declaring he would eat it. (Yes there was an option there, but 'join my team/company/tribe or I'll kill you' isn't much of a choice. It's very familiar with that kind of "bargain.") It could argue any number of things - that the last people that had threatened to kill it were alien remnant-contaminated humans, not any of the people trapped here. Or that there's no feed any anyway humans couldn't read the ID markers without interfaces, which very few of the humans here even seemed familiar with. It could argue that it knows exactly how to keep track of the humans under its protection, thank you, it's not a fucking amateur.
All rational, all feasible. All potential paths to deescalation. Hell, it could even admit that some sort of marker for Convoy members would be a good idea.

But SecUnit knows the kind of person who does this, throws around their weight because they know they can get their way by force, if the first answer isn't the one they want to hear. And it doesn't have to put up with anyone talking condescending shit to it because they think it can't/won't fight back.

Instead, it says, "No one ever gets to brand me ever again." It doesn't even twitch, as Heat comes closer. It doesn't raise those gun arms. The only thing that moves are its eyes, still boring holes into Heat's face - metaphorically, because unlike the shit in Valorant Defenders it doesn't actually have laser beams in its eyes. "And definitely not you or your 'Tribe.'"