When Al orders Sam to keep Susan safe at Ray's home, he tells him it is apartment 218. However, when police later break into the same apartment in order to save Susan from Lonnie, the number of the door is clearly 217.
Some of the riot footage is re-used, for example the same hardware store explosion is seen at around the 30:50 mark and again at around the 34:20 mark.
Captain Paul Brewster refers to Malcolm X in the present tense. However, he was assassinated on February 21, 1965, almost six months before the Watts riots.
The line "I love Ray, Mama Harper" looks and sounds clearly dubbed in.
When Sam is confronted by Susan's father outside their house, when he finishes talking he turns around and the lapel mic transmitter/battery pack is visible on his belt.