battlefield 3 for ps3 comrades train fight issue

when the mission scene starts i walk up the steps to the train tracks then the guy ambushes you, then there are button

seqeuences to press to defend yourself, i dont think it works because everytime i do it i end up dead on the tracks and i

have done it many many times even when the button sequences slightly work i punch the guy then the game blacks out

then 5 miuntes later mission failed it says.

Any help would be appreciated as i would like to move forward in the game