You can get the good samaritain achievement in co-op whether or not the others kill them, and even if YOU shoot at them. As long as you don't actually kill them and get the "naughty-naughty" counter. Your co-op buddy and you can get both the achievements in the same play through. Restart campaign and swap roles to get the other one... works great. BTW these will unlock at beginning of data hive mission if you did it correctly.
"One More Loser!!!"
Last edited by Lofinater23; 09-23-2009 at 07:37 PM.