the first game at arsenal was 1 - 1
the second game at liverpool was 2 - 2 (at that point)
in cup football when two teams are tied after normal time in the second game the "away goals rule" comes into affect
this ineffect doubles the tally of all away goals scored so the aggregate score would have gone from
3-3 to 4-5 in arsenals favour...see?
only if both games have identical scorelines(but in reverse OBV) can a cup game go to extra time and penalties
ANND
can i just say OMFG what a game

was on the edge of my seat the whole time... though was kinda dissappointed with the start we made(arsenal plainly more skilful) after about 25minutes liverpool bossed the game