Although in CGI long shots London is depicted as a Medieval city with dirt roads and gravel paths, in street scenes shot in Seattle clearly show the city as having concrete roads.
Throughout the film, Big Ben constantly reads 3:00, regardless of the actual time established elsewhere in any given scene.
After the massacre on the common, which happens at sundown, The Writer runs home. By the time he dives into a bush after being startled by a tradesman and his young helper, it is night but in the very next scene, taking place only a few minutes later, it is twilight and when he reaches home, it is suddenly day again.
The uniforms worn by the British troops in the film are not correct at all. Most of them appear to be cobbled together from mid to late 20th century USMC Alphas, and many of the other "soldiers" look more like Boer Commandos (right period, wrong country), or Franco's Phalangist/Fascist troops from the Spanish Civil War.
The Artilleryman is shown driving his gun team from the limber box. In reality, he would be riding one of the nearside wheel horses.
The Scientist tells the writer early in the movie that Mars is 40 million miles closer to the Sun than the Earth is. Earth is closer to the Sun than Mars is.
Human skeletons cannot continue to move once all the soft tissue is gone from a human body. Yet, multiple times the skeletons of people killed by the heat rays thrash around for several seconds after only the bones are left.
The same extras are killed several times throughout the film.
When the Writer is showing his wife the planet Mars, the bottom half of the frame is quite obviously bathed in hot summer sunshine, and yet the top half, depicting a matted-in CGI sky, is dark and filled with stars.
The Union Jack flag on the Thunderchild is shown blowing towards the wind as the ship speeds towards the Martian war machine instead of being blown back.
Some of the camera angles on the background plates do not match the angles of the foreground action in the blue screen shots. For example the view from The Writer's bedroom window gives the impression that the ground is at a 45 degree angle to the house, rather than 90 degrees as it should be. Also, whenever anyone is driving a cart, the backgrounds are so mismatched that grass and flowers appear to be over 8 feet tall.
The Writer looks through the observatory telescope with his closed eye.
It is evident that, during the "Thunderchild" scenes, that CGI ships have been layered over stock footage of the sea shot from an aeroplane. The result is that the sea appears to be moving sideways rapidly, not in accordance with the direction that the ships are traveling.
After the narrator flees the pit after the Martians' first attack, the train that passes in the background is a late 20th century Americal diesel model rather than a British steam locomotive.
CGI shots of London do not in any way reflect the actual layout of the city itself; one re-occurring mistake is to show the city filled with Tudor cottages. Very few buildings of the this kind can be found in London as the entire city was destroyed by fire in 1666, prompting a rebuild utilizing only stone and brick.
Much of the Architecture in the street scenes of "London" is, in fact, American; Brownstones, typical of U.S. cities (and definitely not British ones), are seen throughout the film and the in the UK, lamp posts terminating in square lanterns and topped with a hood to reflect light down upon the street have always been favored over the American-style spherical lamps seen in the film.
Modern shop fronts, litter bins and chrome outdoor seating outside a coffee shop can be seen in 1890's "London" (actually Seattle).
People in modern dress can be seen in the far background during some of the street scenes.
When the Westminster clock tower is destroyed, the Houses of Parliament and
Parliament Square are nowhere to be seen. Instead, the Westminster clock tower is depicted as a free-standing tower on the riverbank. In actuality is part of the Parliament buildings.
The Artilleryman, supposedly an Englishman, uses the American pronunciation of "aluminum" as opposed to the English "aluminium".
Parts of London such as Primrose Hill, which have been major urban centers for hundreds of years, are depicted in the film as being empty fields.