This can be done in a private match since the game's ranked matchmaking is so bad. You will need at least 3 players on a team based gametype. Be on the team with 2 players and have the other person on your team get killed. They can blow themselves up or an enemy player can kill them. They will need to be executed or bleed out when in the downed state and respawn. As long as you don't die until the respawn, you will get the achievement.