When JJ Shaft and John Shaft come to JJ's apartment after a night out (when JJ puked on a woman) JJ checks his cellular phone that shows time being 12:27. The clock at the wall seems to be 4:32 only few seconds later.
At the beginning of the movie where Maya is saying goodbye to Shaft before getting into the taxi, there is what looks like a 1998 or later model Mercury Grand Marquis behind the van. But the scene in question is supposed to take place in the early 1990's. This is well before the model came out.
Shaft offers his son an alcoholic drink, then says that JJ would probably prefer a water with lime. JJ then starts to say that lime juice is alkaline and is healthier for you. But lime juice is made up of citric acid (Vitamin C) and would actually make the water acidic.
During a intense shootout scene, Shaft Jr. fires a Ruger LCP .380ACP with purple grip frame , the shell casing is shown to state that the caliber of the round fired is .22, but the shell is clearly a center fire cartridge and NOT a .22 rim fire round.