CCTV pictures recovered by the British police were actually shots taken from a series called ‘KGB Spy’. So, in fact, Skripal poison suspects were British actors in a TV drama, according to a Facebook post by producer Michael Killigan.
Summary
The images of the suspects proof that there is something suspicious about the UK’s evidence: same place, same corridor, same time. But it is impossible for two people to occupy the same space at the same time.
Disproof
There are multiple parallel gates at the Gatwick airport that would have allowed the two suspects pass through the gates at the same time. While the surroundings are identical, the photographs were taken at slightly different angles, indicating different cameras in different positions. Read more by Bellingcat and by Polygraph.