Operation Flashpoint: Red River

In order to unlock this achievement you must finish a mission without having been shot. Your teammates, be it AI or players can get hit. Sent them in first and take cover. Use the tactical map, accessed by , to your advantage and issue orders. If you should die or choose to replay from a checkpoint, the "getting shot" bit will be reset. So if you should get shot, reload a checkpoint or just wait till the last checkpoint in the mission was reached and replay from there.

An easier way to get this without having to play a mission is to start up a Last Stand mission from the Fireteam Engagement mode. As soon as you land move to the defence position. Now you should see an EVAC marker along with green smoke; go there! Your evacuation chopper will come pick you up before wave 1 even started.

The same can be done in Combat Sweep missions where you can choose to go to the EVAC point immediately.

Review 25 September 2014: Added button icons.

Easy way to get this achievement cheaply

Load up the daylight of the Last Stand fireteam engagement.
When the extraction chopper drops you off head towards the main objective.
Wait for Stage 1 Wave 1 to start and stand at the extraction point.(where the smoke is)
Wait for the chopper to land and then have you and your fireteam extract out