The bigger question is how to actually fight with the hands in Battlefield 3?
I am stuck at the part where you have to clear that top floor and you climb the back of the building with another soldier. When the 2 of you enter the bathroom an enemy soldier attacks your mate and you have to get him off your partner. You do this by pressing "o". Then the screen tells you to press something real fast, it just flashes on the screen for a millisecond so I can't tell what it is.
I keep having to repeat this part because I don't know what to press to kill the guy. What do you have to press after pressing the "o"?