I was playing Call of Duty: Modern Warfare for the Wii, and I was in the map Crossfire (I think that's what it's called). I entered a building and was going to see if I could get some kills sniping. I'm using a G3. As soon as I enter the top floor, I see a teammate's dead body, so I aimed down the sight to see a sniper and another opponent in the building opposite of the one I'm in. I was thinking in my head "Oh crap, there's a sniper" so I steadied the camera to get a better shot.
I was right on top of another gun, and on the Wii, you steady the camera by holding the A button, but you can switch weapons by holding the A button when on top of another weapon as well. There was no message telling me about the gun below me, so I accidentally switched weapons. The sniper across shoots, and hits me. I'm almost dead. The weapon that I accidentally switched my G3 out for was a sniper rifle. So then I let my health regenerate a bit, and then I looked through the scope and killed the sniper and the other person in the building with the sniper. After killing them, I went back to pick up my G3 and proceeded out of the building.