I can't comment on the stuff going on outside the ground, or what happened in the family stand, but I can tell you about South Stand Level 1 after the final whistle.
I work for Showsec (save your slating posts for another time :) ), and I was ashamed of our fans yesterday. I got spat on, coins thrown at me, punched in the face and kicked in the legs. The United fans didn't help the situation by goading our fans, but some of the behaviour on show yesterday was shocking.
I love working at City, but being stood inbetween those 2 sets of fans yesterday was pretty terrifying.
To be fair, most of our 'fans' were kids (anyone under 20 to me), but the United fans were all adults and should have known how to behave themselves.