I think the reason why this is a problem for Barca (seemingly losing focus and being complacent after they score a few goals) is that compared to most other teams, Barca has three "states of play" they need to manage and master when they play, as opposed to two. Most other teams mainly have two states: one being "we have the ball, now we attack" and "now we don't have the ball, now we defend". But Barcelona also has a third state of play, and this is "how much should we control the game with passing?".
This third factor is pretty unique to Barcelona, and when the balance is mastered it's one of the things that make our club and our philosophy of play so incredibly effective and good. But it can also work as a double edged sword. That was the problem tonight going into the second half. In the first half they were on a roll, they got the balance between control and directness right, and most importantly - everyone was in sync in understanding this balance. Then comes the break, where I suspect they have been told that they can be a bit more conservative going forward. This is risky, because it can throw a wrench in the flow that the players has established between themselves in the first half - and what do you know, it happened. The result was lack of rhythm, misplaced passes because of confusion between players where they anticipated runs etc.
The players came out and it seemed like half of them wanted to continue with the "directness" needle on the speedometer at 70%, and the other half of players wanted to play at 40%. This resulted in a lack of flow and a lot of confusion between the players. The great understanding they had between eachother was muddled, and City took advantage of it and got a lot of the ball and was allowed to attack WAY too much.
I'm sorry if this came off as rambly, or is hard to make sense of. I have just celebrated our victory with a few beers. (Estrella Damm of course, from a wineglass, as a true gentleman
).