Its easy. Many people say it's impossible to save your buddy on this mission. But I say it's possible.
After sending the gold location, save your game. Quickly go up to cover your buddy. Don't let the enemy shoot your buddy. Use your body to cover him/her (if your buddy is wounded or gives the blue flare you must restart because it's already impossible to save him/her), after you finish all enemies with your buddy still alive he/she will say thank you. If he/she is wounded he/she can't be helped (you can't give him/her a med pack and if you leave him/her will die). If he/she gives you a flare you must give him/her 3 medpacks but he/she will still die, but you will got his/her dessert eagle.
