The parachute Johnny uses at the end of the film changes colors between the wide shot and the close up.
Johnny English and Agent Tucker are in the front seats of the chopper. On the long shot when the chopper takes off, Tucker's seat is empty.
When Johnny is in the restaurant with Agent 1, he drains his glass of wine and agent 1 asks the waitress for another bottle, in the next shot there is a small amount in the bottom of the glass, yet moments later the glass is about a third full.
When English accidentally fires a disc out of the service issue laptop, you'll notice the disc shoot out of the side, exactly the moment he presses "Enter" on the keyboard. However, if you play the very next scene in slow motion, you'll see the disc shoot out again, and this time, English's hand is completely away from the laptop.
After the guy gets shot at the golf course, they load him into the back of the chopper. After Johnny English takes off (at around 40 mins) the back seat of the helicopter is empty.
At the Swiss government fortress, the German designation for the "Vista Lounge" reads "Aussicht Zimmer", which is supposed to be a literal translation of the former, but it is a misspelling (it should read "Aussichtszimmer"). Also the German term for the "Conference Chamber" is misspelled. Instead of "Konferenz Saal" it should read "Konferenzsaal".
During the aerial shot before the MI7 meeting in London, the wording to the bottom right of the "camera" screen says "GEOCACHING". Geocaching is a hobby using GPS to find hidden items, not something which should be on this sort of camera readout.
During the chase in Hong Kong, when Johnny English walks off the pallet after having been craned between buildings, he says Thank You to a builder in Mandarin. His experience should have told him to use Cantonese instead. However, as we saw in the first film, English is highly incompetent in many ways and this may be another.
Kate Sumner is shown to be a behavioral psychologist. Later she administers hypnosis on Johnny English. Behavioral psychologists do administer hypnosis. However she works for MI7 a secret government agency so for all we know these behavioral psychologists could administer hypnosis.
When English visits Tucker at his home, and Tucker is playing a racing game on his laptop, the movements of his car in-game seem to have nothing to do with his actions on the keyboard. When he then stands to close the curtains and talk to English, the car continues to behave as if being controlled, showing that it's just a demo video.
When Johnny English tackles the Queen, the knee pads worn by the stunt double are visible under the pantyhose.
When the killer cleaner is firing the minigun on the golf course, the muzzle flash comes from the centre of the ring of barrels, instead of coming from the end of one of the barrels.
A wounded Karlenko is put aboard the helicopter, lying on the back seat. When the helicopter performs its erratic take-off, however, the back seat is clearly seen to be empty.
At 12m 44s the caption reads "The Grand Lisboa Casino". The two characters actually walk towards the The Grand Lisboa Hotel. The casino is across the road, so they have their backs to it and are walking away from it. It is also called "Casino Lisboa" in real life.
When Johnny is wrestling with Pegasus' mother in the party room, Pegasus' daughter is heard telling Johnny to stop and she sounds as if she is on the other side of the room. However, she is next to him and does not say anything until the end.
When English boards the helicopter he says, "It's just like riding a bike." But, his mouth doesn't move at all during the sentence.
Around 00:46:50, Tucker finish to tell his phrase "... Prime Minister." but his lips are still moving when camera is focus on Johnny.
Simon Ambrose informed the team that Johnny English is the third man in Vortex, resulting in the latter being suspended from the case. Why aren't they suspicious about Ambrose letting him stand in for Pamela?
Compared to the Hong Kong Henchman, Simon Ambrose takes a surprisingly fast recovery after being hit in the groin.