All four Liverpool goals were very avoidable but that's not the point, the point is that Klopp and Hodgson(somewhat?) proved that once you've a go at City, their defense isn't great at all and will likely give you goals.
I don't disagree, but that's too simple without a little detail which prove at times to be very important: refereeing.
I will say the ref in this game is quite good compare to the usual white show. The ref is human and can be influenced by other factors. When it comes to United and Mourinho, the media has negative impression which to some extend influence the weak mentally ref. We are treated as villain and we couldn't get fair call from ref in 50 -50 situation.
This game, both teams are darling of the media. There is no one sided pressure on the ref. Seem like this up the ref performance. Let thing goes when needed. Timely blow whistle. Good decision... Small detail but it helps. On other game, Sterling may get the penalty call or Stones got his ass covered by the ref in Firminio challenge
Tactically, it's not exactly master class. L'pool first goal was intially from a long ball and L'pool attacking unit beat City defensive unit to the bouncing ball and physical battle. One sheer moment of individual brilliance by the Ox made the goal. Defensively we can stop both City and L'pool. We lost to City due to Lukaku having a shocker on both part of the pitch losing like every physical battle and 50/50 ball. Chances, City and L'pool can create but they not exactly getting there against us. For our attackers to be in form and we have a creator like Pogba, our chance on counter attack should be better than the showing in these 2 matches.
In the first half, City still edged L'pool. At the beginning of second half, City still had this edge and had Otamendi scored instead of hitting the bar, the game might be very different which could have killed L'pool momentum. City was blown apart afterward, but as you can see, they have ability to get goals. Had they limited just one goal, they're coming out of this with a draw. They were pretty much close to this draw regardless in reality. Pep pretty much said the same in post match about his team lost control between the conceded goals, but if the game was longer City has the ability to get back into it.
Also remember, City lost Jesus (Pep's preferred forward) and David Silva in this game, which they were fortunately having their service prior in other games.