Continuity mistake: At the police station, just after Cory was killed, the Chief of the precinct is looking at Joe and says "The same son of a b**ch saved the president's life." When the shot cuts to the other guy, then back to Joe and Jimmy outside the office, in the background the chief is now sitting back at his desk - some pretty quick moving between shots. (00:31:40)
Factual error: C4 needs a detonator or blasting cap to explode, and so wouldn't go off from being shot in the trunk of Joe's car. You can even set it on fire and it will just burn slowly. (00:44:35)
Factual error: Senator Calvin Baynard orders police officers to arrest Joe Hallenbeck for crank calling him. In California, a person can only be arrested for a misdemeanor if caught in the act by law enforcement. At the time, harassment (unless it was a threat) by telephone was only a misdemeanor. In 1996 it became a felony due to the passing of the Telecommunications Act Of 1996 signed into law by then-president Bill Clinton. (01:36:59)
Continuity mistake: Marcone goes into the parking lot, notices the white BMW, and shoots out the rear passenger window. The front window is now perfectly intact when previously it was shot at during the limo chase. (01:21:05 - 01:31:15)
Continuity mistake: When Mike's white car gets blown up, it spins in the air and lands the opposite way around, but in a following shot the car has now moved back to facing the same way it did before it blew up. (00:18:00)
Continuity mistake: The whole car lands in the swimming pool, with the back end stuck up in the air and the front end down because of the weight of the engine. A couple of shots later with Darian and the pool owner on the phone, the car is now sat up on its front end, which is now propped up on the side of the pool. (01:18:55 - 01:19:45)
Revealing mistake: When Mike Matthews' car explodes, it's a dummy in the car, not a person.
Answer: You're right, I reviewed the clip. You see Joe holding the briefcase and Jimmy run out of the rich man's house, then get directly into his car. At no time do you see him putting the briefcase anywhere. It's most likely a bad editing job.