You were on a mission and you needed to steal important documents in order to maintain peace between 2 countries. You successfully stole them, but you didn’t think that there might be cameras. And so you fight off your enemies.

Ghost: "I'm empty, cover me!"

After 10 seconds, an SMRS projectile flies near Ghost and hits the enemies.

Ghost: "...what..."

It was clear that he was in shock since you did not take a grenade launcher on the mission