Although this is done intentionally, the dialogue in "Virtues" are written in modern language. Part of the humor of the series is the fact that the characters are wearing ancient costumes but speaking a modern dialect. In any case, it's a goof, even if it's done intentionally, because it's not accurate to ancient times!

The Kams were given a "hot dog" to eat and they all ponder how to eat it and whether or not they should. The history of the hot dog is quite a controversy, being rumored to have originated in different time periods and countries. Although one of the legends does say that it was invented in the 1400's-1600's (Ming dynasty's time period), it's probably inaccurate that the Kams could have been introduced to it.

Nim Fu refers to his wife as "zombie" while he calls himself the "taoist." Taoists were enlisted to combat the zombies. According to Chinese mythology, the term 'jeung see' (zombie) and the actual zombie originated during the Ching dynasty, which occured after the Ming!

How could the Kams know the "Dai Lui Fa" story? "Dai Lui Fa" is an opera play that tells the story of the fall of the Ming dynasty through the sole surviving Ming princess, Cheung Ping, and her lover, scholar Chow Sai Hin. "Virtues" takes place during very 'peaceful' and 'prosperous' time of the Ming.

During the episode when Chan Kiu fears that she might be pregnant again, a midwife walks by and insists that she must be pregnant and says that she can help deliver the baby when it is born because she also helped deliver the birth of Ah Mei, Ah Biu, and Ah Tai. The Seks only moved to the Capital city recently, so how could this midwife have known Kiu and help to deliver her children when they lived in 'Chi Lik Gung' Village before? Unless this midwife also moved to the capital with the Seks, but that is unlikely.

Ah Yuet and Sa Sa dance the tango in an episode with a broom. The tango was not invented until the late 1880's and modified during the 1900's, which was long after the Ming dynasty!

Opium is seen being smoked in several episodes and is regarded as one of the serious social issues in the Ming dynasty. However, the idea of smoking opium in a tabacco pipe was not introduced to China until 1700, during the Ching dynasty. Also, opium wasn't that big of an issue to China until the Ching dynasty, when the British decided that it would be the easiest way to make money off the Chinese. It was during the Ching that opium addiction became a massive problem for China. Also, prior to 1700, opium was primarily used not as a drug, but for medicinal purposes by the Chinese.

How could Man Kwok Kau start visiting prostitutes when he was in his teens? During the episode where he tried to see if he left any "seeds" behind from his past days of sleeping around, the brothel owner showed him some old ladies and said that they had served him since he began visiting brothels 30 years ago. That would mean that Kwok Kau was 12 when he started to visit brothels. How could he have the money to do that then? According to Man Gwai Fei, their family was very poor and lived in the mountains!

Bak Hup became pregnant with Man Kwok Kau in a matter of days after she slept with him. How is it possible that the Imperial Doctor was able to detect her pregnancy so soon?

When Bo Fei forces the "Four Beauties" to make chicken feed as punishment for messing up her hen house, the women come home to dinner very hungry and dirty. Ah Yuet comments that Ah Lo's hair is a mess and Ah Mei's face is dirty. Nim Fu asks if they've been doing manual labor. Because they can't let anyone know about their punishment, Ah Lo lies and says they've been on a shopping spree. However, the goof comes when the women explain why they have symptoms of being exhausted. Ah Mei says she shopped until her hair was a mess and Ah Lo says the sun caused her face to turn black (while the claims against them was the other way around!).

In episode 273, Sa Sa's hair accessories "magically" changes! Her costume is the same, but the accessories in her hair changes during a close-up of her and then reverts back to the original hairstyle after the close-up! Why the sudden change in hair accessories? What was wrong with filming her close-up in her original costume and hair accessories? If they wanted to dress her up, why didn't they do so originally? I highly doubt that they 'forgot' what the exact hair accessories that Kingdom Yuen wore during the initial filming of the scene were. Very strange, but it's quite funny to see her hair change all of a sudden and then change back.

Ah Yuet using syringe needles to vaccinate (as a way to get the "fake" Nim Chi to expose herself) is historically inaccurate (albeit incredibly hilarious). Credit to developing the first syringe with a needle fine enough to pierce the skin belongs to Charles Gabriel Pravaz and Alexander Wood, who did so in 1853! It's unlikely that Ah Yuet could have invented the syringe needles because traditionally, syringes aren't affiliated with Chinese herbal medicine, which was what was used for a long time, especially during the Ming dynasty. The use of syringe needles is most prominent in western medicine and it's very unlikely that Ah Yuet could have gotten them from western traders, especially if they weren't even "invented" until way after the Ming's fall!