Charlie Sheen pulled a prank on Emilio Estevez by saying that he had punched a paparazzo in a restaurant on the night before filming. Sheen took it further by having an on-set police officer who was working security arrest him for assault while he was filming a scene. Estevez was stunned until Sheen returned laughing.
The restaurant where Carl and James eat lunch is called Good Stuff. There are three locations in the Los Angeles area - they filmed at the location in Hermosa Beach on The Strand, which James mentions during lunch as a desired location for the surf shop he and Carl dream of opening.
In his office, Maxwell has an odd looking map showing current daytime in the world in the form of a light source. According to that map, it's daytime in California but when it cuts back and forth to the hitmen he is talking with on the phone, it clearly is nighttime.The "interactive" map could of course be broken or just in need of a battery change which would explain the discrepancy.
In the final scene, the bad guys are off-loading 55-gallon drums of toxic waste from trucks and rolling them down a hill into a lake. However, once the drums land in the water they float, which indicates that the drums are empty.
When we see at night, Carl and James' rival truck drivers waiting in their car at night for the chase, the back window can be seen to be clearly smashed with a hole in the middle. Later on, the same window is not smashed.