Not an interesting game.
Goals happening that were irrelevant to the general play.
Barca's second penalty was a technically correct decision, as I far as I'm concerned, but one that the referee has to really want to give. That is particularly the case when the holding isn't anywhere near the ball, especially in a big game where you espect refs to be fairly reticent about making big calls.
The handball against Robinho was just a bad decision and smacked of a ref deciding to bail out a Barca mistake.
When Ibrahimovic is shit in these game (yes, I know he set up the goal) it really exposes Milan's policy of focusing their game and cash on him, while filling most of the rest of their team with second or third rate players.
Aside from the obvious defensive errors, Milan's attack was very poor. Barcelona's pressing was not good for most of the game and Milan got into heaps of good positions, but poor decisions and poor execution prevented them making chances.
Barca are undoubtedly a team in decline.
When they beat Man Utd in Rome they had great players playing in a great system. They were almost impossible to contain because they had dangerous players all over the place and they made the pitch big and moved the ball fast.
Now their game is almost completely focused on Messi. They don't stretch the pitch the way they used to, so it is easier to block up the midfield and deny Xavi and Iniesta time and space on the ball and, therefore, limit the supply to Messi. Their play is also, in general much slower, which again makes it easier to stop them.