Spoilers ahead for 'Blood Runs Deep' mission.
Like IDred I also tried to do this as total stealth. At first it was going swimmingly. I was able to locate the first guy, and was even able to CQC and fulton him without any notice. Perfect! Then it was on to the mine, a long trek by foot. Using the empty mag, I was able to distract or avoid any of the outposts along the way. My only hiccup was wearing the forest camo in the red clay, but a resupply with the tiger camo took care of that.
So me and Quiet are at the mine. I've been here before, so the AA was destroyed already and I knew about the rear entrance to the mine. Other than inadvertently being briefly detected by the helicopter I was able to sneak my way past everyone. Got to the rear entrance, no problems, it's all peachy.
If I could have only killed those damed kids.
Cut scene, grab the injured kid, and we're heading out. At this point I didn't know that they could given orders. So I'm doing my best to keep up with these little rugrats. We head outside and luckily I have Quiet as a buddy. I'm furiously sending her ahead of me to clear the path, totally forgetting that she can provide cover without any follow on orders.
Now I had wanted to do perfect stealth, but playing chaperone to some kids was taking the priority. Me and Quiet were busy taking turns sending guards to sleepy time when the damned helicopter comes flying overhead. Apparently there is a trigger far enough along the path that alerts the guards, no matter how perfectly stealthy you were. So now I've been detected by the helicopter that came out of nowhere and am running for the pick-up point.
The damed kids. Running, make it to the rescue chopper (get to tha choppa!) and throw on the injured kid. At this point I'd figured that the other kids were right behind, and given that it's the only smart thing to do, jump on with me like Quiet or the dog do. Oh noooo, they're back at the river.
At this point there were guards following behind. I hadn't marked these guys, so I'm turning the corner, running into these guys, and throwing them to the ground. Around this time the kids take off to the chopper. Great, but didn't realize that you had to place them on individually. Ugg...
All this time the rescue chopper has been under fire from the enemy helicopter. Now I've invested in the armor upgrades and missiles, so I figure if the chopper can't hold them off at least he can fight back...right? Nope. By the time it takes me and the kids get back to the chopper it's on fire and crashes to the ground. SNAAAAAAAAKE!!!
Needless to say I was offered the chicken hat after several follow on attempts. The only way I could figure it was to bring along a rocket launcher, but kinda defeats the whole 'Perfect Stealth' I was going for. Ended up getting an A on the follow on attempt. If it wasn't for those pesky kids...