Mesrine, Bauer and Tillier are near a newsstand. Beside, there is a street plan in which a Ford Ka is reflected. A bit later, the three men get into a car which is parked 20 m in frond of a Renault Express. Both these cars were launched later than 1970s (1986 for Renault, 1996 for Ford).
When Mesrine and one of his accomplice run away in metro, one can see tagging. Later, when Mesrine and his friend arrive by car in Spain, there is a small tagged wall. Tagging arrived in France and Spain during the 1980s.
When policemen are looking for Mesrine and Besse, one may see from the air their buses stopped beside a freshly mowed wheat field. Straw is packed in round and wrapped in black plastic (French name for this is "embubanage"). This technique was not invented in the 1970s and straw was squared packed.
There is a tactile paving on Stalingrad metro station : this was not installed at that time. Also, while Mesrine is in the metro, one may see the RATP Green, which is the color of modern Paris metro. At that time, line 2 metro were blue.
In the closing scenes where Mesrine and Sylvie are walking to their car being tracked by the flic the date is given as 2 November 1979. Yet the trees have full green foliage. By November in Paris the trees are bare.
In the scene where a freshly-escaped Mesrine and Besse get on the train, they are shouting at each other and at the passengers, and brandishing pistols, but the extras playing passengers just look bored rather than terrified.
In the first London scene, the red bus has two posters: one for a non-existent film, "Dawn of Evil", and the other for "Tropical Tours". The film poster states "Now playing in theaters (18);" theaters is an Americanism, and wouldn't have been used in the UK, and the 18 certificate did not exist in the 1970s. The telephone number on the other poster is impossible: (01) 7966 0966 has too many digits; London telephone numbers at the time were in the format (01) xxx xxxx.