The Good Liar goofs

Although the film is set in 2009, Roy places the current polymer UK ten-pound note on the counter in the butcher's, rather than the paper note that would have been used at the time.

While Roy and Betty are at Slough railway station, a train with a partly purple livery hurtles through. This is one of the new Elizabeth line units, which as of late 2019 were still being run on a trial basis and did not exist in 2009, the year in which the film is set. Roy also departs on a train carrying GWR branding; in 2009 such services would have worn a First Great Western livery, since the GWR name had not been reinstated until 2015.

The contemporary double-decker buses appearing in several of the film's establishing shots of London were not in service in 2009, the year in which the story is set.

Inside Roy's flat the interior is a single, spacious room featuring a generous bay window with stained-glass detailing, yet from the street the property appears as a modest-sized room with small, flat sash windows. No effort is made to reconcile the interior with the exterior.

The two steaks Roy and Vincent buy from the Russian butcher's do not match the ones later shown in Betty's kitchen — in her kitchen the steaks are cut thicker and appear narrower.

In 2009 Stephen tells Betty and Roy that he is travelling to Spandau Prison to carry out research. The prison was demolished in 1987 — literally pulverised, with its remains scattered at sea — to prevent neo‑Nazis turning it into a shrine. A shopping centre was later built on the site.

The flowers in the painting described as lilies resemble the blooms often called "calla lilies" or "callas". They are not actually members of the lily family, Liliaceae, so they make for a rather curious example of a flower labelled 'lily'...