The final scene of the DT19 taking off from New York shows it off the ground at the very beginning of the runway, even though it's preceded by several scenes of it accelerating down the runway. The exact same scene is used to show the DT19 landing in London - evidently rather than shooting a separate scene for the New York takeoff, they just reused this one and hoped no one would notice.
At the start of this episode, a sniper lowers himself towards the Director General's window on a rope, watch the bottom right of the screen, you can see a hand lowering the puppet.
Colonel White states that London Airport will be sealed for the arrival of the Director-General of the United Asian Republic, so how come DT19 is able to land at the airport.
In the beginning of the episode Captain Grey kills the Mysteron assassin with a regular spectrum pistol, which goes against what we later learn about electricity being the only thing that can kill a Mysteron agent.