I'll have to look at the book again, but I took the impression from the dialogue exchange between two of the mechas that SG had critically damaged if not killed one or more of their compatriots.
"Don't shoot! She's just a kid."
"Tell that to the rest of our squad."
The impression I got from that was that she was a major-league threat (no shit--you gotta nuke aliens from orbit if you want to be sure), regardless of her age. I didn't really read it as she'd killed anybody, although seriously bodily harm may have resulted from punting dudes across the taiga.
If they'd wanted to convey a homicide, I think they would've drawn a dead body, you know?
Oh, it's the usual "It's so much more dramatic/artistic/effective if it's left to the imagination instead of showing it." Sort of like they're saying "I've got nothing against sex. Some of my best friends have sex. Or so they say."
I'm ripping this off next chance I get, man. That's gold.
But that's silly. I mean, you compared it to Watchmen earlier (which, yeah, I doubt it was done better than that, but that's Moore and Gibbons; might as well compare Jerry Jenkins to John Milton). It's not exactly explicit...
And looking into it, from what I saw, if that's the whole thing, this is way less explicit. I was right about it not being as well done, tho.
Then again, I didn't think the scene from the Watchmen movie was goofy, and everyone else did. Maybe "Hallelujah" just wasn't as played out for me as for the average movie watcher.