Factual error: In the Bosphorus scenes, as the ferry crosses from the Asian to the European side of Istanbul, in the distance large trucks can be seen speeding along the coastal road opposite. Well before their time.
Continuity mistake: After Mr. Palmer walks over and tries to pick up Claude Mulvihill's gun (which Jack kicks away) we see Jack's hat on his left. In the next shot as Jake picks it up it's now on his right. (01:19:40)
Plot hole: The killer is not designed to be a ninja with superior athletic and stealth abilities, but for Elsa's death he beats three much younger and able-bodied people who were chasing her, kills the victim unseen by her - and they don't hear her high pitched scream - and is able to get back to the hotel unseen. (00:33:25)
Continuity mistake: Gene Hackman returns a second cookie to Harrison Ford's dish that he hadn't taken - or perhaps it's the same cookie he picked up and returned a moment earlier. Either way, the cookie had suddenly appeared in Hackman's hands going from one shot to another. (00:30:35)