I have seen complaints elsewhere about no extra time and penalty shoot-out after a draw aggregate with same amount of away goals on both sides (examples: [3-1, 1-3], [4-1, 1-4]). So, based on the above posts concerning that [2-1, 0-0], it seems that the system considered the 2nd leg as a single knockout match, neglecting the 1st leg, hence explaining why no extra time and penalty shoot-outs when there should have been or vice versa.