: Yeah, they do so in Halo 1. But as you noted, they don't typically do it in
: the thick of combat, it's usually a small amount of ammunition, and it's
: accompanied by clear aggressive remarks to clarify why the marine is doing
: it.

In H1 I so rarely tackle covies in a hog with Marines, I'd forgotten about this. Evidently it's just like when a Marine on foot runs up to a body and pumps a few more rounds into it while issuing a choice comment. I guess those hog-borne H4 bozos are doing gratuitous shooting then. But I don't recall hearing any comments to make it clear, and that's why it just seemed like an AI failing, as if they were a few seconds slow to realize the enemy was dead.