Revealing mistake: When Tony and Rhodes are on the oil tanker bunkered behind an obstacle, Tony realises his gun is empty and asks Rhodes for a new magazine. When Tony ejects the magazine you can see that it is actually an airsoft gun magazine; thus exposing that it is actually a prop gun.
Continuity mistake: When Tony leaves the bar, his hands are cuffed behind his back. When he is shot at in the next scene after jumping through the window, his hands are somehow cuffed in the front of his body. (01:54:50)
Answer: An independent guy from the UK called Ian. He's made over 3000 of his product and creation "hot gym".