Well yeah, NVGs work the same way too, see the post above where I linked to the post that triggered me hunting for something similar for silencers.
Also, one step at a time... first we find a way to silence ourselves.. then we find a way to fix the AI so that they don't automatically know we killed their buddy via stealth heheh!
Yeah, even with SH's Detection Mod it seems to happen too. However I can say it happens less, cos I have shot guys on a number of ocassions with my newly-silenced rifle and the guy walking ahead didn't know the guy walking behind died cos I did a headshot. However, niphty's suggestion of LOS being a factor might be at play here - the guy walking ahead wasn't looking in my direction.
So, now we need to figure out if SH's Detection Mod is having any effect on AI hearing/knowing stealth kills...
Well, to be honest, even a headshot on someone with a truely silenced weapon will result in noise. Maybe he goes BLARGGGHHH as his skull pops open. Maybe a shot to the chest you get a nice Sploosh of blood all over the place. The problem is that the AI IMMEDIATELY knows which direction YOU are in. The military would love to know how they do that, so they can equip their soldiers with that mod :P And yes, I know the military has a thing now that can tell the general direction of a shot... before some war geek goes off on me. I saw that episode of Futureweapons, too.
But, back on point.. I've never seen good AI. Sure, their friend just exploded. Don't stand in the open, run for cover.. ANY cover. And don't automatically turn towards the guy who did it and stand there waiting to be shot! That's really where my complaint falls. And having looked at the AI routines.. yeah. Good luck :) I'd just like ONCE to be able to kill that bastard in the Duty base where you have to walk through and he says 'Get out of here Stalker' even if you have 100% faction with them!! without one of his buddies 'knowing' he's dead.
I think we're drifting slightly off topic heh, but yeah I know what you mean. A few times I've had the urge to pop the same guy too.. he's just plain irritating.
I think in this case, it's not the AI routines that is at fault, but the faction-management routines. I suggest this because similar problems have happened before in other games, and it's usually the faction-management routines that somehow "alerts" all members in the same faction that one of their brothers have fallen, regardless of how far away they are or whether they have LOS to their fallen comrade.
As an example, in Neverwinter Nights (the original one back in 2002), whenever someone of a faction dies, the code issued a silent "shout" throughout all faction members that something happened, and that put the whole faction on alert (case in point, city guards). Simply removing that line didn't fix the problem, just created more, so modders actually had to practically re-write the entire faction-management routines from scratch.