We’re preeetty sure they didn’t have plastic bottles back in the 1920s, but a recent Downton Abbey promo shot would beg to differ. With Downton’s third season premiere coming up in September in the UK and January in the US a new promotional photo was released on instagram, featuring, among other things a plastic bottle in the background.

Downton Abbey
Michelle Dockery and Allen Leech, featuring no plastic bottles.

This left some fans amused and many more questioning the historical accuracy of the Crawleys’ drawing room. While the humble plastic bottle first came into commercial use in 1047 (still a few decades after the events of Downton’s fifth season), it didn’t come into wider use until the 1960s.

The mistake appears to be unintentional, since the bottle definitely doesn’t fit in with the fireplace arrangement behind Lord Robert and Lady Edith. Nevertheless, fans were quick to react and the photo made headlines online.

The show employs its own historical advisor, Alastair Bruce to maintain period accuracy as much as possible, but with such a huge production, there are bound to be a few slipups here and there. And when Downton falters, eagle-eyed viewers are always quick to spot the mistake. The show has previously been criticised for featuring things like television aerials, double yellow lines, and some anachronistic language -  including 1960s phrases such as "get stuffed" or "get knotted" – among other things.

More: Downton Abbey Hits Record Ratings In The US

At one point, creator Julian Fellowes was so miffed about the accuracy police, that he made the following, rather passive aggressive, statement: "The real problem is with people who are insecure socially, and they think to show how smart they are by picking holes in the programme to promote their own poshness and to show that their knowledge is greater than your knowledge.”

Apply cold water to burned area.

Downton Abbey
The show has been criticised on its historical accuracy below.