A few that spring to mind:
Fraker calling up another gang and ordering up more henchmen to "turn the heat up" in his area. What? Are gangs allied like that and just waiting for each other to call?
The much-touted Cuban (who is going to kill tonight) gets a very unceremonious STONE KILLER-style dummy drop off a building and onto a car, landing in a very peaceful and meditative position.
"That's my shop!" Why'd they have to dub in so many extra lines from Martin Balsam in that scene when his lips weren't even moving. Were they afraid that the audience wasn't going to make the connection that it was his shop after the 3rd time he said it?
Bronson's girlfriend gets killed almost immediately after they have sex... and he's sad for about 2 seconds. Up there with RAMBO FIRST BLOOD PART 2... was this a 1985 thing?
"I'll call an ambulence"... umm, there's a full scale riot and pure bedlam in the streets with dozens of fatalities including several police officers. What makes you think that your 9-1-1 call would result in help any faster than just going to the hospital yourself?
Shooting the bad guy point blank with a LAW launcher. Um.. wouldn't that have killed Bronson too? Also, how did all those gang members instantly realize that their leader had been killed and just suddenly decide to quit rioting? Are gang members like ants?
That weird look that Bronson and Lauter give each other at the end. Huh?