Nonsensical bit in Nicholson Electroplating (SPOILERS)
In the final shootout at the hanger, Phelps massacres military police. They are not even implied to be corrupt or otherwise villainous characters--they are simply doing their job, which is to guard a military installation that Phelps and Biggs are trespassing upon with weapons drawn. One of them can even be heard instructing the others to fire warning shots before shooting to kill the detectives.
Yes, they are impeding the detectives from reaching Mapes. But it seems obvious that there would be more appropriate ways for the LAPD to obtain access to the hanger. This really drew me out of the game and seemed ridiculous.